WordNet (r) 3.0 (2006):

throw up
    v 1: eject the contents of the stomach through the mouth; "After
         drinking too much, the students vomited"; "He purged
         continuously"; "The patient regurgitated the food we gave
         him last night" [syn: vomit, vomit up, purge, cast,
         sick, cat, be sick, disgorge, regorge, retch,
         puke, barf, spew, spue, chuck, upchuck, honk,
         regurgitate, throw up] [ant: keep down]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "throw up":
   abandon, abdicate, abjure, acknowledge defeat, barf, be seasick,
   be sick, boost, bring up, buoy up, cast up, cease, cede, chuck up,
   cry quits, desist from, disgorge, dispense with, dispose of,
   do without, drop, dump, egest, elevate, erect, escalate,
   feed the fish, forgo, forswear, gag, get along without, get rid of,
   give away, give over, give up, hand over, have done with, heave,
   heave the gorge, heft, heighten, heist, hike, hoick, hoist,
   hold up, jerk up, keck, kiss good-bye, knock up, lay down,
   leave off, levitate, lift, lift up, lob, loft, make a sacrifice,
   part with, perk up, puke, quitclaim, raise, raise up, rear,
   rear up, recant, regurgitate, reject, relinquish, render up,
   renounce, resign, retch, retract, rise, roughcast, roughhew,
   run up, sacrifice, set up, sick up, sky, spare, spew, stick up,
   surrender, swear off, up, upbuoy, upcast, upchuck, upheave,
   uphoist, uphold, uplift, upraise, uprear, upthrow, vacate, vomit,
   waive, yield