Dennis or Denis is either the first or last name of a male derived from the Greco-Roman name Dionysius meaning the Thracian god of wine, which is ultimately derived from the Greek Dios (Διός, "of Zeus") combined with Nysos or Nysa (Νυσα), where the young god was raised.. Dionysus (or Dionysos; also known as Bacchus in Roman mythology and associated with the Italic Liber), the Thracian god of wine, represents not only the intoxicating power of wine, but also its social and beneficent influences. He is viewed as the promoter of civilization, a lawgiver, and lover of peace — as well as the patron deity of both agriculture and the theater.
Dionysus is a god of mystery religious rites, such as those practiced in honor of Demeter and Persephone at Eleusis near Athens. In the Thracian mysteries, he wears the "bassaris" or fox-skin, symbolizing new life. (See also Maenads)
The mediaeval Latinised form of the Anglo-Norman surname Le Denys was Dacus, the adjectival form of Dacia, meaning "Danish" or "The Dane". The name became modernised as Denys, then later as Dennis.
Alternative forms and spellings of the name include Denis, Denys, Denish, Deon, Deonne, Deonte, and Dion, Dionice. Diminutive forms include Den, Dennoh, Deno and Denny. The name Sydenie (alternate spellings: Sydney or Sidney) may derive from a village in Normandy called Saint-Denis, although evidence is slim, and results in the diminutive forms Syd and Sid. A medieval diminutive was Dye, from which the names Dyson and Tyson are derived.
Dennis is a very popular English and Irish name, common throughout the English-speaking world.
Denis is a very popular French name, common throughout the Francophone world, but is also a common English, Irish, German, Italian, Dutch, Croatian, Ukrainian, Russian, Bulgarian, Brazilian and Bosnian name.
Dionizy is the Polish version of the name. The Irish name Donnchadh may be anglicised as Denis, but has a different origin. Dionigi or Dionisio are Italian versions of the name, although Denis is quite common in Italy.
Feminine versions of the name include: Denise, Denisa, Deni, Denice, Deniece, Dione, and Dionne.