dissimulation (n.)

late 14c., dissimulacioun, "concealment of reality under a diverse or contrary appearance," from Old French dissimulation (12c.) and directly from Latin dissimulationem (nominative dissimulatio) "a disguising, concealment, dissembling," noun of action from past-participle stem of dissimulare "make unlike, conceal, disguise," from dis- "not, opposite of" (see dis-) + simulare "to make like, imitate, copy, represent," from stem of similis "like, resembling, of the same kind," from Old Latin semol "together," from PIE root *sem- (1) "one; as one, together with."