[1] : The Collaborative International Dictionary of English v.0.48

fatty \fat"ty\, a.
   containing fat, or having the qualities of fat; greasy;
   gross; as, a fatty substance.
   1913 webster

   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.
      1913 webster
see also:
fatty acid fatty clays clay fatty degeneration fatty heart fatty liver 
fatty infiltration fatty tumor 

[2] : WordNet (r) 2.0

fatty
     adj : containing or composed of fat; "fatty food"; "fat tissue"
           syn: fat ant: nonfat
     n : a rotund individual syn: fatso, fat person, roly-poly,
          butterball ant: thin person
     also: fattiest, fattier
see also:
fat nonfat fatso fat person roly-poly butterball 
thin person fattiest fattier 

[3] : Moby Thesaurus II by Grady Ward, 1.0

38 moby thesaurus words for "fatty":
   adipose, blimp, blubbery, buttery, butyraceous, chrismal,
   chrismatory, fat, greasy, heavy, heavyweight, hippo, lardaceous,
   lardy, lump, mucoid, oily, oleaginous, oleic, potbelly, rich,
   roly-poly, sebaceous, sleek, slick, slippery, smooth, soapy, suety,
   swagbelly, tallowy, tub, tub of lard, tun, unctuous, unguent,
   unguentary, unguentous

Fatty >> F Words
Fatty, definition of term: Fatty
fatty_pag1.html

Fatty Tissue >> F Words
Fatty Tissue, definition of term: Fatty Tissue
fatty+tissue_pag1.html

Fatty Acid >> F Words
Fatty Acid, definition of term: Fatty Acid
fatty+acid_pag1.html

Fatty Liver >> F Words
Fatty Liver, definition of term: Fatty Liver
fatty+liver_pag1.html