The Collaborative International Dictionary of English v.0.48:

Oil \Oil\ (oil), n. [OE. oile, OF. oile, F. huile, fr. L. oleum;
   akin to Gr. ?. Cf. Olive.]
   Any one of a great variety of unctuous combustible
   substances, more viscous than and not miscible with water;
   as, olive oil, whale oil, rock oil, etc. They are of animal,
   vegetable, or mineral origin and of varied composition, and
   they are variously used for food, for solvents, for
   anointing, lubrication, illumination, etc. By extension, any
   substance of an oily consistency; as, oil of vitriol.
   [1913 Webster]

   Note: The mineral oils are varieties of petroleum. See
         Petroleum. The vegetable oils are of two classes,
         essential oils (see under Essential), and natural
         oils which in general resemble the animal oils and
         fats. Most of the natural oils and the animal oils and
         fats consist of ethereal salts of glycerin, with a
         large number of organic acids, principally stearic,
         oleic, and palmitic, forming respectively stearin,
         olein, and palmitin. Stearin and palmitin prevail in
         the solid oils and fats, and olein in the liquid oils.
         Mutton tallow, beef tallow, and lard are rich in
         stearin, human fat and palm oil in palmitin, and sperm
         and cod-liver oils in olein. In making soaps, the acids
         leave the glycerin and unite with the soda or potash.
         [1913 Webster]

   Animal oil, Bone oil, Dipple's oil, etc. (Old Chem.), a
      complex oil obtained by the distillation of animal
      substances, as bones. See Bone oil, under Bone.

   Drying oils, Essential oils. (Chem.) See under Drying,
      and Essential.

   Ethereal oil of wine, Heavy oil of wine. (Chem.) See
      under Ethereal.

   Fixed oil. (Chem.) See under Fixed.

   Oil bag (Zool.), a bag, cyst, or gland in animals,
      containing oil.

   Oil beetle (Zool.), any beetle of the genus Meloe and
      allied genera. When disturbed they emit from the joints of
      the legs a yellowish oily liquor. Some species possess
      vesicating properties, and are used instead of
      cantharides.

   Oil box, or Oil cellar (Mach.), a fixed box or reservoir,
      for lubricating a bearing; esp., the box for oil beneath
      the journal of a railway-car axle.

   Oil cake. See under Cake.

   Oil cock, a stopcock connected with an oil cup. See Oil
      cup.

   Oil color.
   (a) A paint made by grinding a coloring substance in oil.
   (b) Such paints, taken in a general sense.
   (b) a painting made from such a paint.

   Oil cup, a cup, or small receptacle, connected with a
      bearing as a lubricator, and usually provided with a wick,
      wire, or adjustable valve for regulating the delivery of
      oil.

   Oil engine, a gas engine worked with the explosive vapor of
      petroleum.

   Oil gas, inflammable gas procured from oil, and used for
      lighting streets, houses, etc.

   Oil gland.
   (a) (Zool.) A gland which secretes oil; especially in birds,
       the large gland at the base of the tail.
   (b) (Bot.) A gland, in some plants, producing oil.

   Oil green, a pale yellowish green, like oil.

   Oil of brick, empyreumatic oil obtained by subjecting a
      brick soaked in oil to distillation at a high temperature,
      -- used by lapidaries as a vehicle for the emery by which
      stones and gems are sawn or cut. --Brande & C.

   Oil of talc, a nostrum made of calcined talc, and famous in
      the 17th century as a cosmetic. [Obs.] --B. Jonson.

   Oil of vitriol (Chem.), strong sulphuric acid; -- so called
      from its oily consistency and from its forming the
      vitriols or sulphates.

   Oil of wine, [OE]nanthic ether. See under [OE]nanthic.

   Oil painting.
   (a) The art of painting in oil colors.
   (b) Any kind of painting of which the pigments are originally
       ground in oil.

   Oil palm (Bot.), a palm tree whose fruit furnishes oil,
      esp. Elaeis Guineensis. See Elaeis.

   Oil sardine (Zool.), an East Indian herring (Clupea
      scombrina), valued for its oil.

   Oil shark (Zool.)
   (a) The liver shark.
   (b) The tope.

   Oil still, a still for hydrocarbons, esp. for petroleum.

   Oil test, a test for determining the temperature at which
      petroleum oils give off vapor which is liable to explode.


   Oil tree. (Bot.)
   (a) A plant of the genus Ricinus (Ricinus communis), from
       the seeds of which castor oil is obtained.
   (b) An Indian tree, the mahwa. See Mahwa.
   (c) The oil palm.

   To burn the midnight oil, to study or work late at night.


   Volatle oils. See Essential oils, under Essential.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Oil \Oil\, v. t. [imp. & p. p. Oiled; p. pr. & vb. n.
   Oiling.]
   To smear or rub over with oil; to lubricate with oil; to
   anoint with oil.
   [1913 Webster]

WordNet (r) 3.0 (2006):

oil
    n 1: a slippery or viscous liquid or liquefiable substance not
         miscible with water
    2: oil paint containing pigment that is used by an artist [syn:
       oil, oil color, oil colour]
    3: a dark oil consisting mainly of hydrocarbons [syn:
       petroleum, crude oil, crude, rock oil, fossil oil,
       oil]
    4: any of a group of liquid edible fats that are obtained from
       plants [syn: vegetable oil, oil]
    v 1: cover with oil, as if by rubbing; "oil the wooden surface"
    2: administer an oil or ointment to ; often in a religious
       ceremony of blessing [syn: anoint, inunct, oil,
       anele, embrocate]

Moby Thesaurus II by Grady Ward, 1.0:

292 Moby Thesaurus words for "oil":
   Barbados tar, Haliver Oil, Macassar oil, absinthe, adipose tissue,
   adulation, aid, alcohol, animal oils, anoint, anthracene oil,
   aquarelle, asphalt-base oil, avocado oil, balm, balsam, bay oil,
   beechnut oil, beef tallow, beeswax, benzine, blandishment, blarney,
   blubber, bone oil, bottlenose oil, briquette, bunker, bunkum,
   burnable, butane, butter, butter up, butterfat, cajolement,
   cajolery, camphor, candlenut oil, canvas, carapa oil, carbon,
   castor oil, cater, cedarwood oil, cerate, charcoal, clear the way,
   clove oil, coal, coal oil, cocoa butter, cod-liver oil, coke,
   collyrium, combustible, compliment, copaiba, copra oil, corn oil,
   creosote, croton oil, dab, daub, demulcent, detonate, doegling oil,
   dope, dose, drag, dress, dripping, drippings, drug, dub, ease,
   easel-picture, edible oil, electricity, embrocate, embrocation,
   emollient, equalize, ethane, ethanol, eucalyptus oil, even,
   expedite, explain, explode, eyewash, eyewater, facilitate,
   fair words, fat, fawning, feed, fill up, finger painting, fireball,
   firing, fish oil, flammable, flammable material, flatten, flattery,
   flaxseed oil, forage, fuel, fuel additive, fuel dope, fuel oil,
   fuel up, fulminate, furnace oil, gas, gas carbon, gas oil, gas up,
   gasoline, get around, ghee, glycerolate, goose grease, gouache,
   grade, grease, grease the ways, grease the wheels, gum spirit,
   harrow, hasten, help along, hempseed oil, heptane, hexane, honey,
   honeyed phrases, honeyed words, illuminant, illuminating gas,
   incense, inflammable, inflammable material, isooctane, jet fuel,
   jolly, kekuna oil, kerosene, kid along, lamp oil, lanolin, lard,
   lard oil, laurel butter, lay, lay it on, lemon oil, level,
   light source, liniment, linseed oil, lipid, lipoma, loose, lotion,
   lubricate, luminant, make clear, make way for, margarine, medicate,
   methane, methanol, mineral oil, mineral seal oil,
   mineral sperm oil, mineral spirits, mow, mutton tallow,
   naphthalene, naphthene-base oil, natural gas, nut oil, octane,
   oil of almonds, oil painting, ointment, oleo, oleomargarine,
   oleoresin, olive oil, open the way, open up, overdo it, painting,
   palaver, palm oil, palm-kernel oil, paraffin, pave the way,
   peanut oil, peat, pentane, perilla oil, petrol, petrolatum,
   petroleum, petroleum benzine, pine oil, pine tar, pine-tar oil,
   plane, planish, plaster, play up to, pomade, poppyseed oil,
   porpoise oil, praise, prepare the way, pretty lies, propane,
   propellant, provender, provision, purvey, quicken, rape oil,
   refuel, remove friction, ricinus oil, road oil, rocket fuel,
   rosin grease, rosin oil, run interference for, salve,
   saturating oil, seal oil, sell, sesame oil, shale naphtha, shave,
   shortening, simplify, slick, slick on, smear, smooth, smooth down,
   smooth out, smooth the way, soap, soap the ways, soft soap,
   soft-soap, soften up, soybean oil, speed, spikenard, stoke,
   stove oil, string along, stroke, suet, sweet nothings, sweet talk,
   sweet words, sycophancy, tallow, technical oil, tempera, top off,
   turf, turpentine, unbar, unblock, unclog, unction, unguent,
   unguentum, unjam, victual, vulnerary, wash, wash drawing, water,
   wax, whale oil, wheedling, wood oil, wool fat



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

OIL
       Operator Identification Language (ELI)


The Free On-line Dictionary of Computing (30 December 2018):

OIL

   1. ["The Architecture of the FAIM-1 Symbolic Multiprocessing
   System", A.  Davis et al, 9th Intl Joint Conf in Artif Intell,
   1985, pp.32-38].

   2. Operator Identification Language.  Used for overloading
   resolution by the Eli compiler-writing system.


Easton's 1897 Bible Dictionary:

Oil
   Only olive oil seems to have been used among the Hebrews. It was
   used for many purposes: for anointing the body or the hair (Ex.
   29:7; 2 Sam. 14:2; Ps. 23:5; 92:10; 104:15; Luke 7:46); in some
   of the offerings (Ex. 29:40; Lev. 7:12; Num. 6:15; 15:4), but
   was excluded from the sin-offering (Lev. 5:11) and the
   jealousy-offering (Num. 5:15); for burning in lamps (Ex. 25:6;
   27:20; Matt. 25:3); for medicinal purposes (Isa. 1:6; Luke
   10:34; James 5:14); and for anointing the dead (Matt. 26:12;
   Luke 23:56).

     It was one of the most valuable products of the country (Deut.
   32:13; Ezek. 16:13), and formed an article of extensive commerce
   with Tyre (27:17).

     The use of it was a sign of gladness (Ps. 92:10; Isa. 61:3),
   and its omission a token of sorrow (2 Sam. 14:2; Matt. 6:17). It
   was very abundant in Galilee. (See OLIVE.)