The Collaborative International Dictionary of English v.0.48:

Daunt \Daunt\ (d[add]nt; 277), v. t. [imp. & p. p. Daunted; p.
   pr. & vb. n. Daunting.] [OF. danter, F. dompter to tame,
   subdue, fr. L. domitare, v. intens. of domare to tame. See
   Tame.]
   1. To overcome; to conquer. [Obs.]
      [1913 Webster]

   2. To repress or subdue the courage of; to check by fear of
      danger; to cow; to intimidate; to dishearten.
      [1913 Webster]

            Some presences daunt and discourage us. --Glanvill.

   Syn: To dismay; appall. See Dismay.
        [1913 Webster]

WordNet (r) 3.0 (2006):

daunt
    v 1: cause to lose courage; "dashed by the refusal" [syn:
         daunt, dash, scare off, pall, frighten off,
         scare away, frighten away, scare]

Moby Thesaurus II by Grady Ward, 1.0:

78 Moby Thesaurus words for "daunt":
   admonish, alarm, appall, awe, baffle, beat down, break, browbeat,
   bulldoze, bully, castrate, caution, clamp down on, coerce, compel,
   cow, cry out against, despotize, deter, discomfit, disconcert,
   discourage, dishearten, dispirit, dissuade, domineer,
   domineer over, enslave, expostulate, faze, foil, frighten,
   frighten off, frustrate, grind, grind down, henpeck, horrify,
   intimidate, keep down, keep under, kid out of, lord it over,
   oppress, overawe, overbear, overmaster, override, press heavy on,
   put off, remonstrate, repress, ride over, ride roughshod over,
   scare, shake, stop, subjugate, suppress, talk out of, terrify,
   terrorize, threaten, thwart, trample down, trample upon,
   tread down, tread upon, tyrannize, tyrannize over, unman, unnerve,
   unpersuade, upset, walk all over, walk over, warn,
   weigh heavy on