WordNet (r) 3.0 (2006):

comeback
    n 1: a quick reply to a question or remark (especially a witty
         or critical one); "it brought a sharp rejoinder from the
         teacher" [syn: rejoinder, retort, return, riposte,
         replication, comeback, counter]
    2: return by a celebrity to some previously successful activity

Moby Thesaurus II by Grady Ward, 1.0:

86 Moby Thesaurus words for "comeback":
   Parthian shot, acknowledgment, answer, answering, antiphon,
   back answer, back talk, backchat, backfire, boomerang,
   caustic remark, convalescence, counter, counterattack,
   counterblast, counterblow, counterfire, counterinsurgency,
   countermeasure, counterrevolution, counterstep, counterstroke,
   crack, cut, cutting remark, defense, dig, dump, echo,
   evasive reply, exchange, fleer, flout, foolery, gibe,
   gibing retort, give-and-take, interchange, jab, jape, jeer, jest,
   leg-pull, mock, parting shot, put-down, put-on, quip, rally,
   reaction, ready reply, receipt, reciprocation, recoil, recovery,
   recuperation, rejoinder, repartee, replication, reply, repost,
   rescript, rescription, respondence, response, responsion,
   responsory, retaliation, retort, return, reverberation, riposte,
   rude reproach, scoff, scurrility, short answer, slam, slap,
   snappy comeback, swipe, taunt, twit, verbal thrust, witty reply,
   witty retort, yes-and-no answer