The Collaborative International Dictionary of English v.0.48:

Olympic games \O*lym"pic games\, or Olympics \O*lym"pics\
   A modified revival of the ancient Olympian games, consisting
   of international athletic games, races, etc., now held once
   in four years, the first having been at Athens in 1896.

   Note: There are now two sets of modern Olympic games, the
         summer games and the winter games. Both had been held
         every four years, in the same year, but in 1998 for the
         first time the winter games began to be held two years
         after the summer games, though each series is still
         held only once every four years. The number and types
         of sports contests held at the olympics has greatly
         expanded from the original number.
         [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

Olympics
    n 1: the modern revival of the ancient games held once every 4
         years in a selected country [syn: Olympic Games,
         Olympics, Olympiad]

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "Olympics":
   Highland games, Olympiad, Olympic games, bout, carousel, concours,
   contest, derby, encounter, engagement, field day, fight, game,
   games, go, gymkhana, joust, match, matching, meet, meeting, rally,
   regatta, rencontre, test, the Olympics, tilt, tournament, tourney,
   track meet, trial