| a natural vegetable or animal oil that is nonvolatile, as lard oil, linseed oil, etc. |
fatty oil n.
A nonvolatile oil of animal or plant derivation, chemically a glyceride of a fatty acid, that is not capable of distillation and that is convertible into a soap by substituting the glycerine with an alkaline base.
fixed oil n.
A nonvolatile oil, especially a fatty oil of vegetable origin.