hydantoin

from WordNet (r) 3.0 (2006)

hydantoin
    n 1: any of a group of anticonvulsant drugs used in treating
         epilepsy

from The Collaborative International Dictionary of English v.0.48

Hydantoin \Hy*dan"to*in\, n. [Hydrogen + allantion.] (Chem.)
   A derivative of urea, {C3H4N2O2}, obtained from allantion, as
   a white, crystalline substance, with a sweetish taste; --
   called also {glycolyl urea}.
   [1913 Webster]