WordNet (r) 3.0 (2006):

playroom
    n 1: a recreation room for noisy activities (parties or
         children's play etc) [syn: rumpus room, playroom, game
         room]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "playroom":
   archery ground, athletic field, badminton court, baseball field,
   basketball court, billiard parlor, bowling alley, bowling green,
   course, court, cricket ground, croquet ground, croquet lawn,
   diamond, fairway, family room, field, football field, game room,
   glaciarium, golf course, golf links, gridiron, gym, gymnasium,
   ice rink, infield, links, outfield, oval, playground,
   playing field, polo ground, pool hall, poolroom, putting green,
   racecourse, racket court, rec room, recreation room, rink,
   rumpus room, skating rink, soccer field, squash court, stretch,
   tennis court, track, turf