Ni -symbol
- nickel
ni·a·cin ['nī-ə-sən] -n
- an acid C 6H 5NO 2of the vitamin B complex found widely in animals and plants and used esp. against pellagra
- nicotinamide called also nicotinic acid
ni·a·cin·amide [,nī-ə-'si-nə-,mīd] -n
- a compound C 6H 6N 2O of the vitamin B complex found esp. as a constituent of coenzymes and used similarly to niacin called also nicotinamide
Ni·ag·a·ra [nī-'a-g(ə-)rə] -n
- an overwhelming flood : torrent
ni·al·amide [nī-'a-lə-,mīd] -n
- a synthetic antidepressant drug C 16H 18N 4O 2that is an inhibitor of monoamine oxidase
nib ['nib] -n
- bill, beak
- the sharpened point of a quill pen
- pen point
- each of the two divisions of a pen point
- a small pointed or projecting part
nib·ble ['ni-bəl] -vb, n
- to bite gently
- to eat or chew in small bits
- to take away bit by bit
- to take gentle, small, or cautious bites
- snack
- to deal with something as if by nibbling
nibble -n
- an act of nibbling
- a very small quantity or portion (as of food)
- snack
- a tentative expression of interest
Ni·be·lung ['nē-bə-,lu̇ŋ] -n
- a member of a race of dwarfs in Germanic legend
- any of the followers of Siegfried
- any of the Burgundian kings in the medieval German Nibelungenlied
nibs ['nibz] -n pl but sing in constr
- an important or self-important person usu. used in the phrases his nibs or her nibs as if a title of honor
NIC -abbr
- network interface card
- newly industrialized country; newly industrializing country
ni·cad ['nī-,kad] -n
- a rechargeable storage battery that has a nickel cathode and a cadmium anode
nice ['nīs] -adj, adv, n
- wanton, dissolute
- coy, reticent
- showing fastidious or finicky tastes : particular
- too nice a palate to enjoy junk food
- exacting in requirements or standards : punctilious
- possessing, marked by, or demanding great or excessive precision and delicacy
- trivial
- pleasing, agreeable
- well-executed
- appropriate, fitting
- not a nice word for a formal occasion
- socially acceptable : well-bred
- virtuous, respectable
- was taught that nice girls don't do that
- polite, kind
- that's nice of you to say
Ni·cene ['nī-,sēn, nī-'] -adj
- of or relating to Nicaea or the Nicaeans
- of or relating to the ecumenical church council held in Nicaea in a.d.325 or to the Nicene Creed
Nicene Creed -n
- a Christian creed expanded from a creed issued by the first Nicene Council, beginning I believe in one God, and used in liturgical worship
nicenel·ly ['nīs-'ne-lē] -adj, n
- marked by euphemism
- prudish
nice·ty ['nī-sə-tē, -stē] -n
- the quality or state of being nice
- an elegant, delicate, or civilized feature
- enjoy the niceties of life
- a fine point or distinction : subtlety
- the niceties of table manners
- careful attention to details : delicate exactness : precision
- delicacy of taste or feeling : fastidiousness
niche ['nich also 'nēsh or 'nish] -n
- a recess in a wall esp. for a statue
- something that resembles a niche
- a place, employment, status, or activity for which a person or thing is best fitted
- a habitat supplying the factors necessary for the existence of an organism or species
- the ecological role of an organism in a community esp. in regard to food consumption
- a specialized market
- to place in or as if in a niche
Ni·chrome ['nī-,krōm] -trademark
- used for an alloy of nickel, chromium, and iron
nick ['nik] -n
- a small notch, groove, or chip
- a small cut or wound
- a break in one strand of two-stranded DNA caused by a missing phosphodiester bond
- a final critical moment
- prison
- police station
- condition
- to jot down : record
- to make a nick in : notch, chip
- to cut into or wound slightly
- to cut short
- cold weather, which nick ed steel and automobile output -- Time
- to catch at the right point or time
- cheat, overcharge
- arrest
- steal
- to make petty attacks : snipe
- to complement one another genetically and produce superior offspring
nick·el ['ni-kəl] -n
- a silver-white hard malleable ductile metallic element capable of a high polish and resistant to corrosion that is used chiefly in alloys and as a catalyst
- the U.S. 5-cent piece regularly containing 25 percent nickel and 75 percent copper
- the Canadian 5-cent piece
- five cents
- a packet containing five dollars worth of an illicit drug (as marijuana) called also nickel bag
- a pass defense in football that employs five defensive backs
nick·elanddime [,ni-kəl-ən-'dīm] -adj
- involving or offering only a small amount of money
- small-time
nickelanddime [,ni-kəld-ən-'dīmd] -vt
- to impair, weaken, or defeat piecemeal (as through a series of small incursions or excessive attention to minor details)
- to treat (as a person or situation) by paying excessive attention to small amounts of money often with a detrimental effect
nick·el·if·er·ous [,ni-kə-'li-f(ə-)rəs] -adj
- containing nickel
nick·el·ode·on [,ni-kə-'lō-dē-ən] -n
- an early movie theater to which admission usu. cost five cents
- jukebox
nickel silver -n
- german silver
nick·er ['ni-kər] -vi, n
- neigh, whinny
nicker -n
- pound
nicknack ['nik-,nak] -n
(variant of knickknack)
- a small trivial article usu. intended for ornament
nick·name ['nik-,nām] -n
- a usu. descriptive name given instead of or in addition to the one belonging to a person, place, or thing
- a familiar form of a proper name (as of a person or a city)
nickname -vt, n
- misname, miscall
- to give a nickname to
ni·co·ti·a·na [ni-,kō-shē-'a-nə, -'ä-nə, -'ā-nə] -n
- any of several tobaccos (as Nicotiana alata) grown for their showy flowers
nic·o·tin·amide [,ni-kə-'tē-nə-,mīd, -'ti-] -n
- niacinamide
nicotinamide adenine dinucleotide -n
- nad
nicotinamide adenine dinucleotide phosphate -n
- nadp
nic·o·tine ['ni-kə-,tēn] -n
- a poisonous alkaloid C 10H 14N 2that is the chief active principle of tobacco and is used as an insecticide
nic·o·tin·ic [,ni-kə-'tē-nik, -'ti-] -adj
- relating to, resembling, producing, or mediating the effects produced by nicotine on nerve fibers at autonomic ganglia and at the neuromuscular junctions of voluntary muscle which increases activity in small doses and inhibits it in larger doses
nicotinic acid -n
- niacin
nic·ti·tate ['nik-tə-,tāt] -vi
- wink
nictitating membrane -n
- a thin membrane found in many vertebrates at the inner angle or beneath the lower lid of the eye and capable of extending across the eyeball
NICU -abbr
- neonatal intensive care unit
NIDDM -abbr
- non-insulin-dependent diabetes mellitus
ni·dic·o·lous [nī-'di-kə-ləs] -adj
- reared for a time in a nest
- living in a nest
- sharing the nest of another kind of animal
ni·di·fi·ca·tion [,ni-də-fə-'kā-shən, ,nī-] -n
- the act, process, or technique of building a nest
ni·dif·u·gous [nī-'di-fyə-gəs] -adj
- leaving the nest soon after hatching
ni·dus ['nī-dəs] -n
- a nest or breeding place
- a place or substance in an animal or plant where bacteria or other organisms lodge and multiply
- a place where something originates, develops, or is located
niece ['nēs] -n
- a daughter of one's brother, sister, brother-in-law, or sister-in-law
- an illegitimate daughter of an ecclesiastic
ni·el·lo [nē-'e-(,)lō] -n
- any of several black enamel-like alloys usu. of sulfur with silver, copper, and lead
- the art or process of decorating metal with incised designs filled with niello
- a piece of metal or an object decorated with niello
niello -vt
- to inlay or ornament with niello
ni·fed·i·pine [nə-'fe-də-,pēn, -pən] -n
- a calcium channel blocker C 17H 18N 2O 6that is a coronary vasodilator used esp. in the treatment of angina pectoris
Nifl·heim ['ni-vəl-,hām] -n
- the abode of the dead in Norse mythology
nif·ty ['nif-tē] -adj, adv
- very good : very attractive : fine
nifty -n
- something that is nifty
- a clever or neatly turned phrase or joke
ni·gel·la [nī-'je-lə] -n
- any of a genus ( Nigella) of erect annual herbs of the buttercup family having dissected threadlike leaves and usu. blue or white flowers
- love-in-a-mist
Ni·gerCon·go [,nī-jər-'käŋ-(,)gō] -n
- a language family that includes the Mande and Kwa branches and that is spoken by most of the indigenous peoples of west, central, and south Africa
nig·gard ['ni-gərd] -n, adj
- a meanly covetous and stingy person : miser
niggard -vi
- to act niggardly
- to treat in a niggardly manner
nig·gard·ly [-lē] -adj, n, adv
- grudgingly mean about spending or granting : begrudging
- provided in meanly limited supply
nig·ger ['ni-gər] -n
- a black person
- a member of any dark-skinned race
- a member of a socially disadvantaged class of persons
- it's time for somebody to lead all of America's nigger s ...all the people who feel left out of the political process -- Ron Dellums
nig·gle ['ni-gəl] -vb, n
- trifle
- to spend too much effort on minor details
- to find fault constantly in a petty way : carp
- she haggles, she niggle s, she wears out our patience -- Virginia Woolf
- gnaw
- to give stingily or in tiny portions
niggle -n
- a trifling doubt, objection, or complaint
nig·gling ['ni-g(ə-)liŋ] -adj, n, adv
- petty
- bothersome or persistent esp. in a petty or tiresome way
nigh ['nī] -adv
- near in place, time, or relationship often used with on, onto, or unto
- nearly, almost
- close, near
- direct, short
- being on the left side
- near
- to draw or come near to : approach
- to draw near
night ['nīt] -n, adj
- the time from dusk to dawn when no sunlight is visible
- an evening or night taken as an occasion or point of time
- an evening set aside for a particular purpose
- the quality or state of being dark
- : a condition or period felt to resemble the darkness of night: as
- a period of dreary inactivity or affliction
- absence of moral values
- the beginning of darkness : nightfall
- of, relating to, or associated with the night
- intended for use at night
- existing, occurring, or functioning at night
- active or functioning best at night
night and day -adv
- all the time : continually
night blindness ['nīt-,blīnd] -n, adj
- reduced visual capacity in faint light (as at night)
nightblooming cereus -n
- any of several night-blooming cacti
- a slender sprawling or climbing cactus ( Selenicereus grandiflorus) often cultivated for its large showy fragrant white flowers
night·cap ['nīt-,kap] -n
- a cloth cap worn with nightclothes
- a usu. alcoholic drink taken at the end of the day
- the final race or contest of a day's sports
- the second game of a baseball doubleheader
night·clothes [-,klō(th)z] -n pl
- garments for wear in bed
night·club [-,kləb] -n
- a place of entertainment open at night usu. serving food and liquor and providing music and space for dancing and often having a floor show
nightclub -vi, n
- to patronize nightclubs
night court -n
- a criminal court in a large city that sits at night (as for rapid disposition of criminal charges and the granting of bail)
night crawler -n
- earthworm
- a large earthworm found on the soil surface at night and used for fish bait
night·dress ['nīt-,dres] -n
- nightgown
- nightclothes
night·fall ['nīt-,fȯl] -n
- the close of the day : dusk
night·glow [-,glō] -n
- airglow seen during the night
night·gown [-,gau̇n] -n
- dressing gown
- a loose garment for wear in bed
night·hawk [-,hȯk] -n
- any of a genus ( Chordeiles) of American nightjars related to the whip-poor-will
- a common European nightjar ( Caprimulgus europaeus)
- a person who habitually is active late at night
night heron -n
- any of various widely distributed nocturnal or crepuscular herons (esp. genus Nycticorax)
night·ie ['nī-tē] -n
- a nightgown for a woman or child
night·in·gale ['nī-tᵊn-,gāl, -tiŋ-] -n
- an Old World thrush ( Luscinia megarhynchossyn. Erithacus megarhynchos) noted for the sweet usu. nocturnal song of the male
- any of various other birds noted for their sweet song or for singing at night
night·jar ['nīt-,jär] -n
- any of a family (Caprimulgidae) of medium-sized long-winged crepuscular or nocturnal birds (as the whip-poor-wills and nighthawks) having a short bill, short legs, and soft mottled plumage and feeding on insects which they catch on the wing called also goatsucker
night latch -n
- a door lock having a spring bolt operated from the outside by a key and from the inside by a knob
night letter -n
- a telegram sent at night at a reduced rate for delivery the following morning
night·life ['nīt-,līf] -n
- the activity of or entertainment provided for pleasure-seekers at night (as in nightclubs)
- establishments providing nightlife
nightlight [-,līt] -n
- a light kept burning throughout the night
night·long [-,lȯŋ] -adj
- lasting the whole night
- through the whole night
night·ly [-lē] -adj
- happening, done, or used by night or every night
- of or relating to the night or every night
nightly -adv
- every night
- at or by night
night·mare ['nīt-,mer] -n, adj, adv
- an evil spirit formerly thought to oppress people during sleep
- a frightening dream that usu. awakens the sleeper
- something (as an experience, situation, or object) having the monstrous character of a nightmare or producing a feeling of anxiety or terror
night owl -n
- a person who keeps late hours at night
night rail [-,rāl] -n
- nightgown
night raven -n
- a bird that cries at night
night rider -n
- a member of a secret band who ride masked at night doing acts of violence for the purpose of punishing or terrorizing
nights ['nīts] -adv
- in the nighttime repeatedly : on any night
night·scope ['nīt-,skōp] -n
- an optical device usu. using infrared radiation that enables a person to see objects in the dark better
night·shade [-,shād] -n
- any of a genus ( Solanumof the family Solanaceae, the nightshade family) of herbs, shrubs, and trees having alternate leaves, cymose flowers, and fruits that are berries and including some poisonous weeds, various ornamentals, and important crop plants (as the potato and eggplant)
- belladonna
night·shirt [-,shərt] -n
- a nightgown resembling a shirt
night·side [-,sīd] -n
- the side of a celestial body (as the earth, the moon, or a planet) not in daylight
night soil -n
- human feces used esp. for fertilizing the soil
night·spot ['nīt-,spät] -n
- nightclub
night·stand [-,stand] -n
- night table
night·stick [-,stik] -n
- a police officer's club
night sweats -n pl
- profuse sweating during sleep that is sometimes a symptom of febrile disease
night table -n
- a small bedside table or stand
night terror -n
- a sudden awakening in dazed terror that occurs in children during slow-wave sleep, is often preceded by a sudden shrill cry uttered in sleep, and is not remembered when the child awakes usu. used in pl.
night·time [-,tīm] -n
- the time from dusk to dawn
night·walk·er [-,wȯ-kər] -n
- a person who roams about at night esp. with criminal intent
- prostitute, streetwalker
NIH -abbr
- National Institutes of Health
- not invented here
ni·hil·ism ['nī-(h)ə-,li-zəm, 'nē-] -n, n or adj, adj
- a viewpoint that traditional values and beliefs are unfounded and that existence is senseless and useless
- a doctrine that denies any objective ground of truth and esp. of moral truths
- a doctrine or belief that conditions in the social organization are so bad as to make destruction desirable for its own sake independent of any constructive program or possibility
- the program of a 19th century Russian party advocating revolutionary reform and using terrorism and assassination
Ni·ke ['nī-kē] -n
- the Greek goddess of victory
nil ['nil] -n, adj
- nothing, zero
nile green -n
- a pale yellow green
Nile perch -n
- a large predaceous food fish ( Lates niloticus) of the rivers and lakes of northern and central Africa that may exceed 200 pounds (91 kilograms) in weight
nil·gai ['nil-,gī] -n
- a large bluish-gray antelope ( Boselaphus tragocamelus) of India and eastern Pakistan with the male having short horns, a black mane, and tuft of long hair on the throat
nill ['nil] -vb
- to be unwilling : will not
- will you nill you, I will marry you -- Shak.
- refuse
Ni·lot·ic [nī-'lä-tik] -adj
- of or relating to the Nile or the peoples of the Nile basin
- of, relating to, or being the languages of the Nilotic people
nil·po·tent ['nil-,pō-tᵊnt] -adj
- equal to zero when raised to some power
nim ['nim] -vb
- steal, filch
- thieve
- any of various games in which counters are laid out in one or more piles and each player in turn draws one or more counters with the object of taking the last counter, forcing the opponent to take it, or taking the most or fewest counters
nim·ble ['nim-bəl] -adj, n, adv
- quick and light in motion : agile
- marked by quick, alert, clever conception, comprehension, or resourcefulness
- responsive, sensitive
nim·bo·stra·tus [,nim-bō-'strā-təs, -'stra-] -n
- a low dark layer of gray cloud usu. producing light continuous rain or snow
nim·bus ['nim-bəs] -n
- a luminous vapor, cloud, or atmosphere about a god or goddess when on earth
- a cloud or atmosphere (as of romance) about a person or thing
- an indication (as a circle) of radiant light or glory about the head of a drawn or sculptured divinity, saint, or sovereign
- a rain cloud
- thunderhead
- cumulus
NIMBY ['nim-bē] -n
- opposition to the locating of something considered undesirable (as a prison or incinerator) in one's neighborhood
NIMH -abbr
- National Institute of Mental Health
ni·mi·e·ty [ni-'mī-ə-tē] -n
- excess, redundancy
nim·i·nypim·i·ny [,ni-mə-nē-'pi-mə-nē] -adj
- affectedly refined : finicky
Nim·rod ['nim-,räd] -n
- a descendant of Ham represented in Genesis as a mighty hunter and a king of Shinar
- hunter
- idiot, jerk
nin·com·poop ['nin-kəm-,püp, 'niŋ-] -n
- fool, simpleton
nine ['nīn] -n, adj, pron, pl in constr
- the ninth in a set or series
- : something having nine units or members: as
- the nine Muses
- a baseball team
- the first or last nine holes of an 18-hole golf course
nine days' wonder -n
- something or someone that creates a short-lived sensation called also nine day wonder
nine·fold ['nīn-,fōld, -'fōld] -adj, adv
- being nine times as great or as many
- having nine units or members
nine·pin [-,pin] -n
- a bowling game resembling tenpins played without the headpin or having the nine pins in a diamond-shaped configuration with one pin in the center
- a pin used in ninepins
ninetofiv·er ['nīn-tə-'fī-vər] -n
- one who works at a job with regular daytime hours
nine·ty ['nīn-tē] -n, adj or n, adj, pron, pl in constr
- the numbers 90 to 99
- the years 90 to 99 in a lifetime or century
nin·hy·drin [nin-'hī-drən] -n
- a poisonous crystalline oxidizing agent C 9H 6O 4used esp. as an analytical reagent
nin·ja ['nin-jə, -(,)jä] -n
- a person trained in ancient Japanese martial arts and employed esp. for espionage and assassinations
nin·ny ['ni-nē] -n
- fool, simpleton
nin·ny·ham·mer ['ni-nē-,ha-mər] -n
- ninny
ni·non ['nē-,nän] -n
- a smooth sheer fabric
ninth ['nīn(t)th] -n, adj or adv
- a musical interval embracing an octave and a second
- the tone at this interval
- a chord containing a ninth
ninth cranial nerve -n
- glossopharyngeal nerve
ni·o·bate ['nī-ə-,bāt] -n
- a salt containing an anionic grouping of niobium and oxygen
Ni·o·be ['nī-ə-bē] -n
- a daughter of Tantalus and wife of Amphion who while weeping for her slain children is turned into a stone from which her tears continue to flow
ni·o·bi·um [nī-'ō-bē-əm] -n
- a lustrous light gray ductile metallic element that resembles tantalum chemically and is used in alloys
nip ['nip] -vb
- to catch hold of and squeeze tightly between two surfaces, edges, or points : pinch, bite
- to pinch in (as a garment)
- a dress nipped at the waist
- to sever by or as if by pinching sharply
- to destroy the growth, progress, or fulfillment of
- to injure or make numb with cold : chill
- snatch, steal
- to defeat by a small margin
- to move briskly, nimbly, or quickly
- to make a quick trip
- : something that nips: as
- a sharp biting comment
- a sharp stinging cold
- a biting or pungent flavor : tang
- the act of nipping : pinch, bite
- the region of a squeezing or crushing device (as a calender) where the rolls or jaws are closest together
- a small portion
- a small quantity of liquor : sip
- a very small bottle of liquor
- to take liquor in nips : tipple
ni·pa ['nē-pə] -n
- thatch made of leaves of the nipa palm
nip and tuck [,nip-ən(d)-'tək] -adj or adv
- being so close that the lead or advantage shifts rapidly from one opponent to another
nipa palm -n
- a southeast Asian palm ( Nipa fruticans) growing chiefly along rivers and estuaries and having a short underground trunk and large erect pinnate leaves
nip·per ['ni-pər] -n
- any of various devices (as pincers) for nipping usu. used in pl.
- a boy employed as a helper (as of a carter or hawker)
- child
- a small boy
nipping [-lē] -adj, adv
- sharp, chilling
nip·ple ['ni-pəl] -n, adj
- the protuberance of a mammary gland upon which in the female the lactiferous ducts open and from which milk is drawn
- an artificial teat through which a bottle-fed infant nurses
- a device with an orifice through which the discharge of a liquid can be regulated
- a protuberance resembling or suggesting the nipple of a breast
- a small projection through which oil or grease is injected into machinery
- a pipe coupling consisting of a short piece of threaded tubing
Nip·pon·ese [,ni-pə-'nēz, -'nēs] -adj, n
- japanese
nip·py ['ni-pē] -adj, adv, n
- marked by a tendency to nip
- brisk, quick, or nimble in movement : snappy
- pungent, sharp
- chilly, chilling
nipup ['nip-,əp] -n
- a spring from a supine position to a standing position
ni·qab [ni-'käb] -n
- a veil for covering the hair and face except for the eyes that is worn by some Muslim women
nir·va·na [nir-'vä-nə, (,)nər-] -n, adj
- the final beatitude that transcends suffering, karma, and samsara and is sought esp. in Buddhism through the extinction of desire and individual consciousness
- a place or state of oblivion to care, pain, or external reality
- bliss, heaven
- a goal hoped for but apparently unattainable : dream
Ni·san ['ni-sᵊn, nē-'sän] -n
- the seventh month of the civil year or the first month of the ecclesiastical year in the Jewish calendar
ni·sei [nē-'sā, 'nē-,] -n
- a son or daughter of Japanese immigrants who is born and educated in America and esp. in the U.S.
ni·si ['nī-,sī] -adj
- taking effect at a specified time unless previously modified or avoided by cause shown, further proceedings, or a condition fulfilled
Nis·sen hut ['ni-sᵊn-] -n
- a prefabricated shelter with a semicircular arching roof of corrugated iron sheeting and a concrete floor
NIST -abbr
- National Institute of Standards and Technology
ni·sus ['nī-səs] -n
- a mental or physical effort to attain an end : a perfective urge or endeavor
nit ['nit] -n
- the egg of a louse or other parasitic insect
- the insect itself when young
- a minor shortcoming
- nitwit
NIT -abbr
- National Invitational Tournament
nite ['nīt] -n, adj
(variant of night)
- the time from dusk to dawn when no sunlight is visible
- an evening or night taken as an occasion or point of time
- an evening set aside for a particular purpose
- the quality or state of being dark
- : a condition or period felt to resemble the darkness of night: as
- a period of dreary inactivity or affliction
- absence of moral values
- the beginning of darkness : nightfall
- of, relating to, or associated with the night
- intended for use at night
- existing, occurring, or functioning at night
- active or functioning best at night
ni·ter ['nī-tər] -n
- potassium nitrate
- chile saltpeter
nit·ery ['nī-tə-rē] -n
- nightclub
nit·id ['ni-təd] -adj
- bright, lustrous
ni·ti·nol ['nī-tə-,nȯl, -,nōl] -n
- a nonmagnetic alloy of titanium and nickel that after being deformed returns to its original shape upon being reheated
nit·pick ['nit-,pik] -vb, n, adj
- to engage in nit-picking
- to criticize by nit-picking
nitpick·ing ['nit-,pi-kiŋ] -n
- minute and usu. unjustified criticism
nitr- -comb form
- nitrogen
- containing the monovalent group NO 2
ni·trate ['nī-,trāt, -trət] -n
- a salt or ester of nitric acid
- sodium nitrate or potassium nitrate used as a fertilizer
nitrate of soda
- sodium nitrate used as a fertilizer
ni·tra·tion [nī-'trā-shən] -n, vt
- the process of adding a nitro group to an organic compound
ni·tre ['nī-tər] -n
(variant of niter)
- potassium nitrate
- chile saltpeter
ni·tric acid ['nī-trik-] -n
- a corrosive liquid inorganic acid HNO 3used esp. as an oxidizing agent, in nitrations, and in making organic compounds (as fertilizers, explosives, and dyes)
nitric oxide -n
- a colorless poisonous gas NO formed by oxidation of nitrogen or ammonia that is present in the atmosphere and also in mammals where it is synthesized from arginine and oxygen and acts as a vasodilator and as a mediator of cell-to-cell communication
ni·tride ['nī-,trīd] -n
- a binary compound of nitrogen with a more electropositive element
nitride -vt
- to case-harden (as steel) by causing the surface to absorb nitrogen
ni·tri·fi·ca·tion [,nī-trə-fə-'kā-shən] -n
- the oxidation (as by bacteria) of ammonium salts to nitrites and the further oxidation of nitrites to nitrates
ni·tri·fi·er ['nī-trə-,fī(-ə)r] -n
- any of the nitrifying bacteria
ni·tri·fy·ing ['nī-trə-,fī-iŋ] -adj
- active in or relating to nitrification
nitrifying bacteria -n pl
- bacteria of a family (Nitrobacteraceae) comprising gram-negative bacteria commonly found in the soil and obtaining energy through the process of nitrification
ni·trile ['nī-trəl, -,trī(-ə)l] -n
- an organic cyanide containing the group CN which on hydrolysis yields an acid with elimination of ammonia
ni·trite ['nī-,trīt] -n
- a salt or ester of nitrous acid
ni·tro ['nī-(,)trō] -adj
- containing or being the monovalent group NO 2united through nitrogen
nitro -n
- any of various nitrated products
- nitroglycerin
ni·tro·ben·zene [,nī-trō-'ben-,zēn, -ben-'] -n
- a poisonous yellow oily liquid C 6H 5NO 2with an almond odor that is used esp. in chemical synthesis (as of aniline)
ni·tro·cel·lu·lose [-'sel-yə-,lōs, -,lōz] -n
- any of several nitric-acid esters of cellulose used esp. for making explosives, plastics, and varnishes
ni·tro·fu·ran [,nī-trō-'fyu̇r-,an, -fyu̇-'ran] -n
- any of several nitro derivatives of furan used as bacteria-inhibiting agents
ni·tro·gen ['nī-trə-jən] -n, adj
- a colorless tasteless odorless element that as a diatomic gas is relatively inert and constitutes 78 percent of the atmosphere and that is a constituent of organic compounds found in all living tissues
ni·tro·ge·nase [nī-'trä-jə-,nās, 'nī-trə-jə-, -,nāz] -n
- an enzyme of various nitrogen-fixing bacteria that catalyzes the reduction of molecular nitrogen to ammonia
nitrogen balance -n
- the difference between nitrogen intake and nitrogen loss in the body or the soil
nitrogen cycle -n
- a continuous series of natural processes by which nitrogen passes successively from air to soil to organisms and back to air or soil involving principally nitrogen fixation, nitrification, decay, and denitrification
nitrogen dioxide -n
- a toxic reddish brown gas NO 2that is a strong oxidizing agent, is produced by combustion (as of fossil fuels), and is an atmospheric pollutant (as in smog)
nitrogen fixation -n
- the conversion of atmospheric nitrogen into a combined form (as ammonia) through chemical and esp. biological action (as that of soil rhizobia)
nitrogenfixer -n
- any of various soil microorganisms that are involved in nitrogen fixation
nitrogenfixing -adj
- capable of nitrogen fixation
nitrogen mustard -n
- any of various toxic blistering compounds analogous to mustard gas but containing nitrogen instead of sulfur
nitrogen narcosis -n
- a state of euphoria and confusion similar to that of alcohol intoxication which occurs when nitrogen in normal air enters the bloodstream at increased pressure (as in deep-water diving) called also rapture of the deep
nitrogen oxide -n
- : any of several oxides of nitrogen most of which are produced in combustion and are considered to be atmospheric pollutants: as
- nitric oxide
- nitrogen dioxide
- nitrous oxide
nitrogen tetroxide -n
- a colorless toxic gas N 2O 4that is a dimer of nitrogen dioxide and that in liquid form is used as an oxidizer in rocket engines
ni·tro·glyc·er·in [,nī-trə-'glis-rən, -'gli-sə-] -n
- an oily explosive poisonous liquid C 3H 5N 3O 9used chiefly in making dynamite and in medicine as a vasodilator
ni·tro·meth·ane [,nī-trō-'me-,thān, Brit usu -'mē-] -n
- a liquid nitroparaffin CH 3NO 2that is used as an industrial solvent, in chemical synthesis, and as a fuel for rockets and high-performance engines
ni·tro·par·af·fin [-'pa-rə-fən] -n
- any of various nitro derivatives of alkanes
nitros- -comb form
- containing the group NO
ni·tro·sa·mine [nī-'trō-sə-,mēn] -n
- any of various organic compounds which are characterized by the grouping NNO and some of which are powerful carcinogens
ni·trous ['nī-trəs] -adj
- of, relating to, or containing niter
nitrous acid -n
- an unstable acid HNO 2known only in solution or in the form of its salts or esters
nitrous oxide -n
- a colorless gas N 2O that when inhaled produces loss of sensibility to pain preceded by exhilaration and sometimes laughter, that is used esp. as an anesthetic in dentistry and as a fuel, and that is an atmospheric pollutant and greenhouse gas produced by combustion called also laughing gas
nit·tygrit·ty ['ni-tē-,gri-tē, ,ni-tē-'] -n, adj
- what is essential and basic : specific practical details
- get down to the nittygritty of the problem
nit·wit ['nit-,wit] -n
- a scatterbrained or stupid person
NIU -abbr
- network interface unit
nix ['niks] -n
- nothing
- veto, reject
- the court nix ed the merger
- no used to express disagreement or the withholding of permission often used with on
- they said nix on our plan
- a water sprite of Germanic folklore
nix·ie ['nik-sē] -n
- nix
ni·zam [ni-'zäm, 'nī-,zam, nī-'] -n
- one of a line of sovereigns of Hyderabad, India, reigning from 1713 to 1950