homing device: the mechanism in a guided missile that guides it toward its objective
mechanism: device consisting of a piece of machinery; has moving parts that perform some function
antisocial personality disorder: a personality disorder characterized by amorality and lack of affect; capable of violent acts without guilt feelings (`psychopathic personality' was once widely used but was superseded by `sociopathic personality' to indicate the social aspects of the disorder, but now `antisocial personality disorder' is the preferred term)