- any of a group of oily, organic liquids occurring naturally, as linseed, soybean, or dehydrated castor oil, or synthesized, that when applied as a thin coating absorb atmospheric oxygen, forming a tough, elastic layer.
- one of a number of animal or vegetable oils, such as linseed oil, that harden by oxidation on exposure to air: used as a base for some paints and varnishes
