WordNet (r) 3.0 (2006):

prizefighter
    n 1: a professional boxer [syn: prizefighter, gladiator]

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "prizefighter":
   Chinese boxer, bantamweight, black belt, boxer, brown belt,
   bruiser, featherweight, fighter, fisticuffer, flyweight,
   heavyweight, karate expert, light heavyweight, lightweight,
   middleweight, palooka, pug, pugilist, savate expert, sparrer,
   welterweight