WordNet (r) 3.0 (2006):

playboy
    n 1: a man devoted to the pursuit of pleasure [syn: playboy,
         man-about-town, Corinthian]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "playboy":
   Casanova, Don Juan, Lothario, Romeo, bon vivant, carouser, clubman,
   clubwoman, contestant, cutup, debauchee, excellent companion,
   frisker, frolicker, funmaker, gamboler, gay dog, good company,
   good mixer, joiner, lady-killer, man-about-town, merrymaker, mixer,
   nightclub habitue, player, pleasant company, pleasure-seeker,
   pleasurer, pleasurist, rake, reveler, rollicker, roue, skylarker,
   social lion, wolf, womanizer