Source : Webster's Revised Unabridged Dictionary (1913)

Triglyceride \Tri*glyc"er*ide\, n. [Pref. tri- + glyceride.]
   (Chem.)
   A glyceride formed by the replacement of three hydrogen atoms
   in glycerin by acid radicals.

Source : WordNet®

triglyceride
     n : glyceride occurring naturally in animal and vegetable
         tissues; it consists of three individual fatty acids
         bound together in a single large molecule; an important
         energy source forming much of the fat stored by the body