[Fr., from L. oleum.] Greasy substances expressed or drawn from various animal, vegetable, and mineral bodies, as olive oil, whale oil, rock oil, etc. They are used for food, for solvents, for anointing, lubrication, illumination, etc. The mineral oils are varieties of petroleum. The vegetable oils are of two classes-essential oils 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 glycerine, with a large number of organic acids, principally stearic, oleic, and palmitic, forming respectively stearin, olein, audpalmitin. Mutton tallow, beef tallow, and lard are rich in stearin, human fat and palm oil in palmitin, and sperm and codliver in olein. Oils are classified according to their properties, and include-(1) non-drying oils, as almond, mustard, olive, etc.; (2) drying oils, as linseed, walnut, poppy, hemp, etc.; (3) train and fish oils, as seal, sperm, whale, cod, etc.; (4) vegetable fats, as palm oil, cocoa-nut oil, etc.; (5) animal fats, as lard, butter, tallow, etc.; and (6) waxes, as palm-tree wax, bees-wax, etc.