ul·cer ['əl-sər] -n, vb

  1. a break in skin or mucous membrane with loss of surface tissue, disintegration and necrosis of epithelial tissue, and often pus
  2. something that festers and corrupts like an open sore

ul·cer·ate ['əl-sə-,rāt] -vb

  1. to become affected with or as if with an ulcer
  2. to affect with or as if with an ulcer

ul·cer·a·tion [,əl-sə-'rā-shən] -n, adj

  1. the process of becoming ulcerated : the state of being ulcerated
  2. ulcer

ulcerative colitis -n

  1. a nonspecific inflammatory disease of the colon of unknown cause characterized by diarrhea with discharge of mucus and blood, cramping abdominal pain, and inflammation and edema of the mucous membrane with patches of ulceration

ul·cero·gen·ic [,əl-sə-rō-'je-nik] -adj

  1. tending to produce or develop into ulcers or ulceration

ul·cer·ous ['əls-rəs, 'əl-sə-] -adj

  1. characterized or caused by ulceration
    • ulcerous lesions
  2. affected with or as if with an ulcer : ulcerated

ule·ma [,ü-lə-'mä] -n

  1. the body of mullahs
  2. mullah

ulex·ite ['yü-lək-,sīt] -n

  1. a soft mineral consisting of a hydrous borate of sodium and calcium and usu. occurring in loose masses of white fibers

ul·lage ['ə-lij] -n

  1. the amount that a container (as a tank or cask) lacks of being full

ul·na ['əl-nə] -n, adj

  1. the bone on the little-finger side of the human forearm
  2. a corresponding part of the forelimb of vertebrates above fishes

ul·ster ['əl-stər] -n

  1. a long loose overcoat of Irish origin made of heavy material (as frieze)

ult -abbr

  1. ultimo

ul·te·ri·or [,əl-'tir-ē-ər] -adj, adv

  1. further, future
  2. more distant : remoter
  3. situated on the farther side : thither
  4. going beyond what is openly said or shown and esp. what is proper
    • ulterior motives

ul·ti·ma ['əl-tə-mə] -n

  1. the last syllable of a word

ul·ti·ma·cy ['əl-tə-mə-sē] -n

  1. the quality or state of being ultimate
  2. ultimate

ul·ti·ma ra·tio [,u̇l-tə-mə-'rä-tē-,ō] -n

  1. the final argument
  2. the last resort (as force)

ul·ti·mate ['əl-tə-mət] -adj, n

  1. most remote in space or time : farthest
  2. last in a progression or series : final
    • their ultimate destination was Paris
  3. eventual
    • they hoped for ultimate success
  4. the best or most extreme of its kind : utmost
    • the ultimate sacrifice
  5. arrived at as the last result
    • the ultimate question
  6. basic, fundamental
    • the ultimate nature of things -- A. N. Whitehead
  7. original
    • the ultimate source
  8. incapable of further analysis, division, or separation

ultimate -n

  1. something ultimate
  2. fundamental
  3. acme

ul·ti·mate [-mət, -,māt] -vb

  1. end

ul·ti·mate·ly [-mət-lē] -adv

  1. in the end : fundamentally
    • the word comes ultimately from Latin
  2. eventually
    • ultimately, they agreed

ul·ti·ma Thu·le [,əl-tə-mə-'thü-lē, -'thyü-] -n

  1. thule

ul·ti·ma·tum [,əl-tə-'mā-təm, -'mä-] -n

  1. a final proposition, condition, or demand
  2. one whose rejection will end negotiations and cause a resort to force or other direct action

ul·ti·mo ['əl-tə-,mō] -adj

  1. of or occurring in the month preceding the present

ul·ti·mo·gen·i·ture [,əl-tə-mō-'je-nə-,chu̇r, -ni-chər, -nə-,tyu̇r, -nə-,tu̇r] -n

  1. a system of inheritance by which the youngest child succeeds to the estate

ul·tra ['əl-trə] -adj

  1. going beyond others or beyond due limit : extreme

ultra -n

  1. one that is ultra : extremist

ultra- -prefix

  1. beyond in space : on the other side : trans-
    • ultra violet
  2. beyond the range or limits of : transcending : super-
    • ultra microscopic
  3. beyond what is ordinary, proper, or moderate : excessively : extremely
    • ultra modern

ul·tra·ba·sic [,əl-trə-'bā-sik] -adj, n

  1. extremely basic
  2. very low in silica and rich in iron and magnesium minerals

ul·tra·cen·trif·u·gal [-,sen-'tri-fyə-gəl, -fi-gəl] -adj, adv

  1. of, relating to, or obtained by means of an ultracentrifuge

ul·tra·cen·tri·fuge [-'sen-trə-,fyüj] -n

  1. a high-speed centrifuge able to sediment colloidal and other small particles and used esp. in determining sizes of such particles and molecular weights of large molecules

ultracentrifuge [-,sen-trə-fyu̇-'gā-shən] -vt, n

  1. to subject to an ultracentrifuge

ul·tra·fiche ['əl-trə-,fēsh] -n

  1. a microfiche whose microimages are of printed matter reduced 90 or more times

ul·tra·fil·tra·tion [,əl-trə-fil-'trā-shən] -n

  1. filtration through a medium (as a semipermeable capillary wall) which allows small molecules (as of water) to pass but holds back larger ones (as of protein)

ul·tra·high frequency [,əl-trə-'hī-] -n

  1. a radio frequency between superhigh frequency and very high frequency

ul·tra·ism ['əl-trə-,i-zəm] -n, adj or n, adj

  1. the principles of those who advocate extreme measures (as radicalism)
  2. an instance or example of radicalism

ul·tra·light ['əl-trə-,līt] -adj

  1. extremely light in mass or weight
    • an ultralight alloy
    • an ultralight pullover

ultralight -n

  1. a very light recreational aircraft typically for one person that is powered by a small gasoline engine

ul·tra·maf·ic [,əl-trə-'ma-fik] -adj

  1. ultrabasic

ul·tra·mar·a·thon [-'ma-rə-,thän] -n

  1. a footrace longer than a marathon

ul·tra·ma·rine [-mə-'rēn] -n

  1. a blue pigment prepared by powdering lapis lazuli
  2. a similar pigment prepared from kaolin, soda ash, sulfur, and charcoal
  3. any of several related pigments
  4. a vivid blue

ultramarine -adj

  1. situated beyond the sea

ul·tra·mi·cro [,əl-trə-'mī-(,)krō] -adj

  1. being or dealing with something smaller than micro

ul·tra·mi·cro·scope [,əl-trə-'mī-krə-,skōp] -n

  1. an apparatus for making visible by scattered light particles too small to be perceived by an ordinary microscope

ul·tra·mi·cro·scop·ic [-,mī-krə-'skä-pik] -adj, adv

  1. too small to be seen with an ordinary microscope
  2. of or relating to an ultramicroscope

ul·tra·mi·cro·tome [-'mī-krə-,tōm] -n

  1. a microtome for cutting extremely thin sections for electron microscopy

ul·tra·min·i·a·ture [-'mi-nē-ə-,chu̇r, -'mi-ni-,chu̇r, -'min-yə-, -chər, -,tyu̇r, -,tu̇r] -adj

  1. subminiature

ul·tra·mon·tane [-'män-,tān, -,män-'] -adj, n

  1. of or relating to countries or peoples beyond the mountains (as the Alps)
  2. favoring greater or absolute supremacy of papal over national or diocesan authority in the Roman Catholic Church

ul·trapas·teur·ized [-'pas-chə-,rīzd, -'pas-tyə-, -tə-] -adj

  1. subjected to pasteurization at higher than normal temperatures esp. to extend shelf life
    • ultrapasteurized cream

ul·tra·short [-'shȯrt] -adj

  1. having a wavelength below 10 meters
    • ultrashort radiation
  2. very short in duration
    • an ultrashort pulse of light

ul·tra·son·ic [-'sä-nik] -adj, adv

  1. having a frequency above the human ear's audibility limit of about 20,000 hertz used of waves and vibrations
  2. utilizing, produced by, or relating to ultrasonic waves or vibrations
    • ultrasonic testing of metal

ul·tra·son·ics [,əl-trə-'sä-niks] -n pl

  1. ultrasonic vibrations or compressional waves
  2. the study of ultrasonic vibrations and their associated phenomena
  3. ultrasonic devices

ul·tra·so·nog·ra·phy [-sə-'nä-grə-fē, -sō-] -n, adj

  1. ultrasound

ul·tra·sound ['əl-trə-,sau̇nd] -n

  1. vibrations of the same physical nature as sound but with frequencies above the range of human hearing
  2. the diagnostic or therapeutic use of ultrasound and esp. a noninvasive technique involving the formation of a two-dimensional image used for the examination and measurement of internal body structures and the detection of bodily abnormalities called also sonography
  3. a diagnostic examination using ultrasound

ul·tra·struc·ture ['əl-trə-,strək-chər] -n, adj, adv

  1. biological structure and esp. fine structure (as of a cell) not visible through an ordinary microscope

ul·tra·vi·o·let [,əl-trə-'vī-(ə-)lət] -adj, n

  1. situated beyond the visible spectrum at its violet end used of radiation having a wavelength shorter than wavelengths of visible light and longer than those of X-rays
  2. relating to, producing, or employing ultraviolet radiation

ul·tra vi·res [,əl-trə-'vī-(,)rēz] -adv or adj

  1. beyond the scope or in excess of legal power or authority

ul·u·lant ['əl-yə-lənt, 'yül-] -adj

  1. having a howling sound : wailing
    • dark wasteland...ululant with bitter wind -- Rudi Blesh

ul·u·late ['əl-yə-,lāt, 'yül-] -vi, n

  1. howl, wail

ul·va ['əl-və] -n

  1. sea lettuce

Ulys·ses [yu̇-'li-(,)sēz] -n

  1. odysseus