dis·sem·ble 
(dĭ-sĕmbəl)
(dĭ-sĕmbəl)v. dis·sem·bled, dis·sem·bling, dis·sem·bles
v.intr.
To disguise or conceal one's real nature, motives, or feelings behind a false appearance.
v.tr.
To disguise or conceal behind a false appearance. See Synonyms at disguise.
[Middle English dissemblen, from Old French dessembler, to be different : des-, dis- + sembler, to appear, seem; see SEMBLABLE.]
dis·semblance n.
dis·sembler n.
dis·sembling·ly adv.