Source : Webster's Revised Unabridged Dictionary (1913)

Anhydride \An*hy"dride\, n. [See {Anhydrous}.] (Chem.)
   An oxide of a nonmetallic body or an organic radical, capable
   of forming an acid by uniting with the elements of water; --
   so called because it may be formed from an acid by the
   abstraction of water.

Source : WordNet®

anhydride
     n : a compound formed from one or more other compounds in a
         reaction resulting in removal of water