WordNet (r) 3.0 (2006):

whoop it up
    v 1: celebrate noisily, often indulging in drinking; engage in
         uproarious festivities; "The members of the wedding party
         made merry all night"; "Let's whoop it up--the boss is
         gone!" [syn: revel, racket, make whoopie, make
         merry, make happy, whoop it up, jollify, wassail]

Moby Thesaurus II by Grady Ward, 1.0:

60 Moby Thesaurus words for "whoop it up":
   be enthusiastic, be noisy, brawl, bubble over, carouse, carry on,
   carry on over, celebrate, chirm, clamor, clangor, cut loose,
   cut up, cut up rough, debauch, effervesce, enthuse, go on,
   go on over, gush, gush over, hell around, horse around, jollify,
   jolly, lark, let go, let loose, let off steam, maffick,
   make a noise, make a racket, make an uproar, make merry,
   make much of, make whoopee, noise, racket, raise Cain,
   raise a clamor, raise hell, raise sand, raise the deuce,
   raise the devil, raise the roof, rave, rave about, revel,
   rhapsodize, roar, roister, roughhouse, row, rumpus, see life,
   skylark, spree, step out, take on over, wanton