The Collaborative International Dictionary of English v.0.48:

Scoff \Scoff\, v. i. [imp. & p. p. Scoffed (?; 115); p. pr. &
   vb. n. Scoffing.] [Cf. Dan. skuffe to deceive, delude,
   Icel. skopa to scoff, OD. schoppen. See Scoff, n.]
   To show insolent ridicule or mockery; to manifest contempt by
   derisive acts or language; -- often with at.
   [1913 Webster]

         Truth from his lips prevailed with double sway,
         And fools who came to scoff, remained to pray.
                                                  --Goldsmith.
   [1913 Webster]

         God's better gift they scoff at and refuse. --Cowper.
   [1913 Webster]

   Syn: To sneer; mock; gibe; jeer. See Sneer.
        [1913 Webster]

WordNet (r) 3.0 (2006):

scoffing
    n 1: showing your contempt by derision [syn: jeer, jeering,
         mockery, scoff, scoffing]

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "scoffing":
   Humism, Pyrrhonism, abusive, agnosticism, banter, bantering,
   blackening, blameful, booing, catcalling, censorious, chaffing,
   condemnatory, contemptuous, damnatory, denunciatory, deprecative,
   deprecatory, depreciative, derision, derisive, derisory,
   disparaging, doubt, execrating, execrative, execratory, fleering,
   flippancy, flippant, fooling, grinning, hissing, hooting,
   incredulity, invective, inveighing, jeering, joshing, judgmental,
   kidding, leering, levity, mockery, mocking, objurgatory, panning,
   priggish, quizzical, ragging, railing, raillery, rallying, razzing,
   reproachful, reprobative, reviling, ridicule, ridiculing, roasting,
   skepticism, smart, smart-aleckiness, smart-alecky, smart-ass,
   smartness, smirking, sneering, snickering, sniggering, snorting,
   taunting, teasing, twitting, vilifying, vituperative