WordNet (r) 3.0 (2006):

give up
    v 1: lose (s.th.) or lose the right to (s.th.) by some error,
         offense, or crime; "you've forfeited your right to name
         your successor"; "forfeited property" [syn: forfeit,
         give up, throw overboard, waive, forgo, forego]
         [ant: arrogate, claim, lay claim]
    2: give up with the intent of never claiming again; "Abandon
       your life to God"; "She gave up her children to her ex-
       husband when she moved to Tahiti"; "We gave the drowning
       victim up for dead" [syn: abandon, give up]
    3: give up in the face of defeat of lacking hope; admit defeat;
       "In the second round, the challenger gave up" [syn: drop
       out, give up, fall by the wayside, drop by the
       wayside, throw in, throw in the towel, quit, chuck up
       the sponge] [ant: enter, participate]
    4: put an end to a state or an activity; "Quit teasing your
       little brother" [syn: discontinue, stop, cease, give
       up, quit, lay off] [ant: bear on, carry on,
       continue, preserve, uphold]
    5: give up what is not strictly needed; "he asked if they could
       spare one of their horses to speed his journey" [syn:
       spare, give up, part with, dispense with]
    6: part with a possession or right; "I am relinquishing my
       bedroom to the long-term house guest"; "resign a claim to the
       throne" [syn: release, relinquish, resign, free,
       give up]
    7: leave (a job, post, or position) voluntarily; "She vacated
       the position when she got pregnant"; "The chairman resigned
       when he was found to have misappropriated funds" [syn:
       vacate, resign, renounce, give up]
    8: relinquish possession or control over; "The squatters had to
       surrender the building after the police moved in" [syn:
       surrender, cede, deliver, give up]
    9: give up or agree to forgo to the power or possession of
       another; "The last Taleban fighters finally surrendered"
       [syn: surrender, give up] [ant: hold out, resist,
       stand firm, withstand]
    10: stop maintaining or insisting on; of ideas or claims; "He
        abandoned the thought of asking for her hand in marriage";
        "Both sides have to give up some claims in these
        negotiations" [syn: abandon, give up]
    11: allow the other (baseball) team to score; "give up a run"
        [syn: give up, allow]
    12: stop consuming; "kick a habit"; "give up alcohol" [syn:
        kick, give up]

Moby Thesaurus II by Grady Ward, 1.0:

111 Moby Thesaurus words for "give up":
   abandon, abandon hope, abdicate, abjure, acknowledge defeat,
   back down, be at sea, be innocent of, be lost, be pensioned,
   be superannuated, break off combat, break the habit, cave in,
   cease, cease resistance, cede, come off, coquet with, cry quits,
   cut out, dabble, demit, desist, desist from, despair, despair of,
   despond, discontinue, disgorge, dispense with, dispose of, disuse,
   do without, drop, dump, falter, forgo, forswear, get along without,
   get rid of, give away, give ground, give in, give over,
   give up hope, give way, hand, hand over, have done with,
   have no idea, kick, kiss good-bye, know a little, know not,
   know not what, know nothing of, lay down, leave, leave off, let go,
   lose heart, lose hope, make a sacrifice, make nothing of, nol-pros,
   not know, not pursue with, not rightly know, not understand,
   part with, pass, pension off, put behind one, quit, quit the field,
   quitclaim, recant, relinquish, render up, renounce,
   renounce the throne, resign, retire, retire from office, retract,
   sacrifice, scratch the surface, shake, sink into despair, smatter,
   spare, stand aside, stand down, step aside, stop, superannuate,
   surrender, swear off, take the pledge, throw off, throw up,
   toy with, vacate, waive, withdraw from, wonder, wonder whether,
   wot not of, yield, yield to despair