Roman god of fertility and wine. The Latin name is derived from the Greek Bákchos (Doinysos) whose cult was implanted in Rome at a comparatively early date. It was a secret cult and it's rites, the Bacchanalia, were mared not only be sexual excesses but by crimes of every description, so much so that from time to time the cult was prohibited. The most significant portrayal of Dionysiac mysteries is to be found in Pompeii.
Source: Lurker, Manfred; Dictionary of Gods and Goddesses, Devils and Demons. Routledge, London, 1988.