oid·i·um [ō-'i-dē-əm] -n

  1. any of a genus ( Oidiumof the family Moniliaceae) of imperfect fungi many of which are now considered to be conidial stages of various powdery mildews
  2. one of the small conidia borne in chains by various fungi (as an oidium) called also arthrospore
  3. a powdery mildew esp. of grapes caused by an oidium

oil ['ȯi(-ə)l] -n

  1. any of numerous unctuous combustible substances that are liquid or can be liquefied easily on warming, are soluble in ether but not in water, and leave a greasy stain on paper or cloth
  2. petroleum
  3. the petroleum industry
  4. a substance (as a cosmetic preparation) of oily consistency
    • bath oil
  5. an oil color used by an artist
  6. a painting done in oil colors
  7. unctuous or flattering speech
  8. to smear, rub over, furnish, or lubricate with oil
  9. to take on fuel oil

oil beetle -n

  1. any of various blister beetles (genus Meloeor a related genus) that emit a yellowish liquid from the leg joints when disturbed

oil·bird ['ȯi(-ə)l-,bərd] -n

  1. a nocturnal bird ( Steatornis caripensis) of northern So. America and Trinidad that is related to the nightjars, feeds chiefly on the fatty fruits of various palms, and has fatty young from which an oil used esp. in cooking is extracted called also guacharo

oil cake -n

  1. the solid residue after extracting the oil from seeds (as of cotton)

oil·can ['ȯi(-ə)l-,kan] -n

  1. a can for oil
  2. a spouted can designed to release oil drop by drop (as for lubricating machinery)

oil·cloth [-,klȯth] -n

  1. cloth treated with oil or paint and used for table and shelf coverings

oil color -n

  1. a pigment used for oil paint
  2. oil paint

oiled ['ȯi(-ə)ld] -adj

  1. lubricated, treated, or covered with or as if with oil
    • oiled paper
  2. drunk

oil·er ['ȯi-lər] -n

  1. a person who oils something
  2. a receptacle or device for applying oil
  3. oilskin
  4. an auxiliary naval vessel used for refueling at sea

oil field -n

  1. a region rich in petroleum deposits
  2. one that has been brought into production

oil gland -n

  1. : a gland (as of the skin) that produces an oily secretion: as
  2. a sebaceous gland
  3. uropygial gland

oil·man ['ȯi(-ə)l-mən, -,man] -n

  1. an oil company executive
  2. an oil field worker

oil of vitriol

  1. concentrated sulfuric acid

oil of wintergreen

  1. the methyl ester of salicylic acid that is used as a flavoring and as a counterirritant

oil paint -n

  1. paint in which a drying oil is the vehicle

oil painting -n

  1. the act or art of painting in oil colors
  2. a picture painted in oils
  3. painting that uses pigments orig. ground in oil

oil palm -n

  1. an African pinnate-leaved palm ( Elaeis guineensis) cultivated for its clustered fruit whose flesh and seeds yield oil

oil pan -n

  1. the lower section of the crankcase used as a lubricating-oil reservoir on an internal combustion engine

oil patch -n

  1. oil field
  2. the petroleum industry

oil·seed ['ȯi(-ə)l-,sēd] -n

  1. a seed or crop (as flaxseed) grown mainly for oil

oil shale -n

  1. a rock (as shale) from which oil can be recovered by distillation

oil·skin ['ȯi(-ə)l-,skin] -n

  1. an oiled waterproof cloth used for coverings and garments
  2. an oilskin raincoat
  3. an oilskin suit of coat and trousers

oil slick -n

  1. a film of oil floating on water

oil·stone ['ȯi(-ə)l-,stōn] -n

  1. a whetstone for use with oil

oil well -n

  1. a well from which petroleum is obtained

oily ['ȯi-lē] -adj, adv, n

  1. of, relating to, or consisting of oil
  2. covered or impregnated with oil
    • oily rags
  3. relatively high in naturally secreted oils
    • oily skin
    • oily hair
  4. excessively smooth or suave in manner

oink ['ȯiŋk] -n, vi

  1. the natural noise of a hog

oint·ment ['ȯint-mənt] -n

  1. a salve or unguent for application to the skin

oi·ti·ci·ca [,ȯi-tə-'sē-kə] -n

  1. any of several So. American trees
  2. a Brazilian tree ( Licania rigida) with seeds that yield a drying oil similar to tung oil