HOCUS POCUS, a cant expression with which the exhibitors of legerdemain tricks generally prefaced their feats. They are thought to be derived from that arch legerdemain trick of the Romish priests converting the sacramental bread into Deity; in which wonderful metamorphosis the words hoc est corpus made a conspicuous part of the ceremony, and which words may be considered as the probable root of our modern hocus-pocus.