The Collaborative International Dictionary of English v.0.48:

Derisive \De*ri"sive\, a.
   Expressing, serving for, or characterized by, derision.
   "Derisive taunts." --Pope. -- De*ri"sive*ly, adv. --
   De*ri"sive*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

derisive
    adj 1: abusing vocally; expressing contempt or ridicule;
           "derisive laughter"; "a jeering crowd"; "her mocking
           smile"; "taunting shouts of `coward' and `sissy'" [syn:
           derisive, gibelike, jeering, mocking, taunting]

Moby Thesaurus II by Grady Ward, 1.0:

122 Moby Thesaurus words for "derisive":
   abusive, arrogant, audacious, aweless, back-biting, bantering,
   belittling, biggety, bitchy, blackening, blameful, bluff, bold,
   booing, brash, brassy, brazen, bumptious, calumniatory, calumnious,
   catcalling, catty, censorious, chaffing, challenging, cheeky,
   chutzpadik, cocky, condemnatory, contemptuous, contumelious,
   crusty, damnatory, daring, defamatory, defiant, defying,
   denunciatory, deprecative, deprecatory, depreciative, depreciatory,
   derisory, derogative, derogatory, detractory, discourteous,
   disdainful, disparaging, disregardful, disrespectful, execrating,
   execrative, execratory, facy, fleering, flip, flippant, fooling,
   fresh, gally, gratuitous, greatly daring, grinning, hissing,
   hooting, impertinent, impudent, insolent, invective, inveighing,
   irreverent, jeering, joshing, judgmental, kidding, leering,
   libelous, malapert, minimizing, mocking, nervy, objurgatory,
   panning, pejorative, pert, priggish, quizzical, ragging, railing,
   rallying, razzing, regardless of consequences, reproachful,
   reprobative, reviling, ridiculing, roasting, rude, sassy, saucy,
   scandalous, scoffing, scurrile, scurrilous, slanderous, slighting,
   smart, smart-alecky, smart-ass, smirking, sneering, snickering,
   sniggering, snorting, taunting, teasing, twitting, uncalled-for,
   vilifying, vituperative, wise-ass