The Collaborative International Dictionary of English v.0.48:

Masque \Masque\, n.
   A mask; a masquerade.
   [1913 Webster]

WordNet (r) 3.0 (2006):

masque
    n 1: a party of guests wearing costumes and masks [syn:
         masquerade, masquerade party, masque, mask]

Moby Thesaurus II by Grady Ward, 1.0:

151 Moby Thesaurus words for "masque":
   Grand Guignol, Kaffeeklatsch, Passion play, Tom show, antimasque,
   audience success, bal, bal costume, bal masque, ball, ballet,
   barn dance, blowout, bomb, broadcast drama, burlesque show,
   camouflage, charade, cliff hanger, closet drama, cocktail party,
   coffee klatch, comedy drama, costume party, country dance,
   critical success, dance, daytime serial, dialogue, dinner,
   dinner party, disguise, documentary drama, domino, donation party,
   drama, dramalogue, dramatic play, dramatic series, duodrama,
   duologue, entertainment, epic theater, experimental theater,
   extravaganza, failure, false colors, false face, false front,
   fancy-dress ball, festivity, flop, garden party, gasser, giveaway,
   happening, hen party, hit, hit show, hop, house party,
   house-raising, housewarming, improvisational drama, incognito,
   lawn party, legitimate drama, mask, masked ball, masquerade,
   masquerade ball, masquerade party, melodrama, minstrel show,
   miracle, miracle play, mixer, monodrama, monologue, morality,
   morality play, mummery, music drama, musical revue, mystery,
   mystery play, opera, pageant, panel show, pantomime, party,
   pastoral, pastoral drama, piece, play, playlet, problem play, prom,
   promenade, protective coloration, psychodrama, quiz show,
   radio drama, record hop, review, revue, sensational play, serial,
   shindig, shindy, show, shower, sitcom, situation comedy, sketch,
   skit, smoke screen, smoker, soap, soap opera, sociodrama,
   spectacle, square dance, stag, stag dance, stag party, stage play,
   stage show, straight drama, success, surprise party,
   suspense drama, tableau, tableau vivant, talk show, tea dance,
   teleplay, television drama, television play, the dansant,
   theater of cruelty, total theater, variety show, vaudeville,
   vaudeville show, vehicle, visor, vizard, vizard mask,
   word-of-mouth success, work