The Collaborative International Dictionary of English v.0.48:

Anti-Semitism \An`ti-Sem"i*tism\, n.
   Opposition to, or hatred of, Semites, esp. Jews. The word is
   sometimes also applied to acts motivated by or evincing
   antisemitism. -- An`ti-Sem"ite, n. -- An`ti-Sem*it"ic, a.
   [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

anti-Semite
    adj 1: discriminatory especially on the basis of race or
           religion [syn: racist, antiblack, anti-Semite(a)]
    n 1: someone who hates and would persecute Jews [syn: anti-
         Semite, Jew-baiter]