1. a slippery or viscous liquid or liquefiable substance not miscible with water
2. oil paint containing pigment that is used by an artist
3. a dark oil consisting mainly of hydrocarbons
4. any of a group of liquid edible fats that are obtained from plants
5. Any one of a great variety of unctuous combustible substances, 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.
6. cover with oil, as if by rubbing
oil the wooden surface
7. administer an oil or ointment to ; often in a religious ceremony of blessing
8. To smear or rub over with oil; to lubricate with oil; to anoint with oil.