Source : Webster's Revised Unabridged Dictionary (1913)

Dissimulate \Dis*sim"u*late\, a. [L. dissimulatus, p. p. of
   dissimulare. See {Dissemble}.]
   Feigning; simulating; pretending. [Obs.] --Henryson.

Dissimulate \Dis*sim"u*late\, v. i.
   To dissemble; to feign; to pretend.

Source : WordNet®

dissimulate
     v : hide (feelings) from other people