Dennis \d(en)-nis\ as a boy's name is pronounced DEN-iss. It is of Greek and English origin, and the meaning of Dennis is "follower of Dionysius". Also variant of Dionysius. Mythology: Dionysius is the Greek god of wine, responsible for the growth of the vines in spring and the originator of winemaking; he is equivalent to the Roman god Bacchus. Biblical: a judge of Athens who was converted to Christianity by the apostle Paul. Basketball player Dennis Rodman; actors Dennis Quaid, Dennis Christopher, Dennis Hopper, Dennis Franz, Denis Leary, Dennis Haysbert; sailor Dennis Conner.