WordNet (r) 3.0 (2006):

schmuck
    n 1: (Yiddish) a jerk [syn: schmuck, shmuck, schmo,
         shmo]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "schmuck":
   ass, born fool, buffoon, clown, doodle, egregious ass,
   figure of fun, fool, idiot, ignoramus, jackass, jerk, lunatic,
   milksop, mooncalf, nincompoop, ninny, perfect fool, softhead, sop,
   stupid ass, tomfool, zany