The Collaborative International Dictionary of English v.0.48:

Horridly \Hor"rid*ly\, adv.
   In a horrid manner. --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

horridly
    adv 1: in a hideous manner; "her face was hideously disfigured
           after the accident" [syn: hideously, horridly,
           monstrously]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "horridly":
   abominably, alarmingly, appallingly, astoundingly, atrociously,
   awfully, banefully, basely, bestially, brutally, contemptibly,
   despicably, detestably, direly, disconcertingly, disgustingly,
   dismayingly, dreadful, dreadfully, egregiously, fearfully,
   flagrantly, forbiddingly, foully, frightfully, fulsomely, ghastly,
   grimly, grossly, gruesomely, hideously, horrendously, horribly,
   horrifically, horrifyingly, infamously, loathsomely, nastily,
   nauseatingly, notoriously, obnoxiously, odiously, offensively,
   outrageously, repugnantly, repulsively, revoltingly, savagely,
   scandalously, shabbily, shamefully, shockingly, something fierce,
   sordidly, startlingly, terribly, terrifically, tragically,
   tremendously, viciously, vilely, wretchedly