28 Moby Thesaurus words for "costume party":
   Kaffeeklatsch, ball, blowout, cocktail party, coffee klatch,
   dinner, dinner party, donation party, entertainment, festivity,
   garden party, hen party, house party, house-raising, housewarming,
   lawn party, mask, masque, masquerade, masquerade party, party,
   shindig, shindy, shower, smoker, stag, stag party,
   surprise party