Source : Webster's Revised Unabridged Dictionary (1913)

Trisaccharide \Tri*sac"cha*ride\, n. Also -rid \-rid\ (Chem.)
   A complex sugar, as raffinose, yielding by hydrolysis three
   simple sugar molecules.

Source : WordNet®

trisaccharide
     n : any of a variety of carbohydrates that yield three
         monosaccharide molecules on complete hydrolysis