Dennis is a male first name derived from the Greco-Roman name Dionysius meaning "servant of Dionysus", the Thracian god of wine, which is ultimately derived from the Greek Dios (????, "of Zeus") combined with Nysos or Nysa (????), where the young god was raised.Alternative forms and spellings of the name include Denis, Denys, Deon, Deonne, Deonte, and Dion, Dionice. Diminutive forms include Den and Denny. The name Sydenie (alternate spellings: Sydney or Sidney) derives from a village in Normandy