The Collaborative International Dictionary of English v.0.48:

Bacchus \Bac"chus\, n. [L., fr. Gr. Ba`kchos.] (Myth.)
   The god of wine, son of Jupiter and Semele.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Bacchus
    n 1: (classical mythology) god of wine; equivalent of Dionysus

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "Bacchus":
   Agdistis, Amor, Aphrodite, Apollo, Apollon, Ares, Artemis, Ate,
   Athena, Ceres, Cora, Cronus, Cupid, Cybele, Demeter, Despoina,
   Diana, Dionysus, Dis, Eros, Gaea, Gaia, Ge, Great Mother, Hades,
   Helios, Hephaestus, Hera, Here, Hermes, Hestia, Hymen, Hyperion,
   Jove, Juno, Jupiter, Jupiter Fidius, Jupiter Fulgur,
   Jupiter Optimus Maximus, Jupiter Pluvius, Jupiter Tonans, Kore,
   Kronos, Magna Mater, Mars, Mercury, Minerva, Mithras, Momus,
   Neptune, Nike, Olympians, Olympic gods, Ops, Orcus, Persephassa,
   Persephone, Phoebus, Phoebus Apollo, Pluto, Poseidon, Proserpina,
   Proserpine, Rhea, Saturn, Tellus, Venus, Vesta, Vulcan, Zeus,
   bacchanalianism, bibaciousness, bibacity, bibulosity, bibulousness,
   crapulence, crapulousness, intemperance, serious drinking,
   sottishness



The Devil's Dictionary (1881-1906):

BACCHUS, n.  A convenient deity invented by the ancients as an excuse
for getting drunk.

    Is public worship, then, a sin,
        That for devotions paid to Bacchus
    The lictors dare to run us in,
        And resolutely thump and whack us?
                                                                Jorace