Fat″ty (?), a. Containing fat, or having the qualities of fat; greasy; gross; as, a fatty substance.
Fatty acid(Chem.), any one of the paraffin series of monocarbonic acids, as formic acid, acetic, etc.; — so called because the higher members, as stearic and palmitic acids, occur in the natural fats, and are themselves fatlike substances. — Fatty clays. See under Clay. — Fatty degeneration(Med.), a diseased condition, in which the oil globules, naturally present in certain organs, are so multiplied as gradually to destroy and replace the efficient parts of these organs. — Fatty heart, Fatty liver, etc. (Med.), a heart, liver, etc., which have been the subjects of fatty degeneration or infiltration. — Fatty infiltration(Med.), a condition in which there is an excessive accumulation of fat in an organ, without destruction of any essential parts of the latter. — Fatty tumor(Med.), a tumor consisting of fatty or adipose tissue; lipoma.