dissimilate (v.)

"make different, cause to be unlike," 1821, on model of assimilate, from dis- + Latin similis "like, resembling, of the same kind," from Old Latin semol "together," from PIE root *sem- (1) "one; as one, together with." In linguistics, of sounds, "to become unlike, to diverge," by 1860. Related: Dissimilated; dissimilating.