The Collaborative International Dictionary of English v.0.48:

Feign \Feign\, v. t. [imp. & p. p. Feigned; p. pr. & vb. n.
   Feigning.] [OE. feinen, F. feindre (p. pr. feignant), fr.
   L. fingere; akin to L. figura figure,and E. dough. See
   Dough, and cf. Figure, Faint, Effigy, Fiction.]
   1. To give a mental existence to, as to something not real or
      actual; to imagine; to invent; hence, to pretend; to form
      and relate as if true.
      [1913 Webster]

            There are no such things done as thou sayest, but
            thou feignest them out of thine own heart. --Neh.
                                                  vi. 8.
      [1913 Webster]

            The poet
            Did feign that Orpheus drew trees, stones, and
            floods.                               --Shak.
      [1913 Webster]

   2. To represent by a false appearance of; to pretend; to
      counterfeit; as, to feign a sickness. --Shak.
      [1913 Webster]

   3. To dissemble; to conceal. [Obs.] --Spenser.
      [1913 Webster]

WordNet (r) 3.0 (2006):

feign
    v 1: make believe with the intent to deceive; "He feigned that
         he was ill"; "He shammed a headache" [syn: feign, sham,
         pretend, affect, dissemble]
    2: make a pretence of; "She assumed indifference, even though
       she was seething with anger"; "he feigned sleep" [syn:
       simulate, assume, sham, feign]

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "feign":
   act, act a part, affect, assume, bluff, counterfeit, cover up,
   dissemble, dissimulate, do a bit, dramatize, fake, four-flush,
   gammon, histrionize, let on, let on like, make a pretense,
   make as if, make believe, make like, make out like, overact, play,
   play a part, play a scene, play possum, playact, pretend, profess,
   put on, put on airs, sham, simulate, tug the heartstrings, wear