The Collaborative International Dictionary of English v.0.48:

Succinimide \Suc`cin*im"ide\, n. (Chem.)
   A white crystalline nitrogenous substance, C2H4.(CO)2.NH,
   obtained by treating succinic anhydride with ammonia gas. It
   is a typical imido acid, and forms a series of salts. See
   Imido acid, under Imido.
   [1913 Webster]