\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.