The Collaborative International Dictionary of English v.0.48:

Deity \De"i*ty\ (d[=e]"[i^]*t[y^]), n.; pl. Deities
   (d[=e]"[i^]*t[i^]z). [OE. deite, F. d['e]it['e], fr. L.
   deitas, fr. deus a god; akin to divus divine, Jupiter, gen.
   Jovis, Jupiter, dies day, Gr. di^os divine, Zey`s, gen.
   Dio`s, Zeus, Skr. d[=e]va divine, as a noun, god, daiva
   divine, dy[=o] sky, day, hence, the sky personified as a god,
   and to the first syllable of E. Tuesday, Gael. & Ir. dia God,
   W. duw. Cf. Divine, Journey, Journal, Tuesday.]
   1. The collection of attributes which make up the nature of a
      god; divinity; godhead; as, the deity of the Supreme Being
      is seen in his works.
      [1913 Webster]

            They declared with emphasis the perfect deity and
            the perfect manhood of Christ.        --Milman.
      [1913 Webster]

   2. A god or goddess; a heathen god.
      [1913 Webster]

            To worship calves, the deities
            Of Egypt.                             --Milton.
      [1913 Webster]

   The Deity, God, the Supreme Being.
      [1913 Webster]

            This great poet and philosopher [Simonides], the
            more he contemplated the nature of the Deity, found
            that he waded but the more out of his depth.
                                                  --Addison.
      [1913 Webster]

WordNet (r) 3.0 (2006):

deity
    n 1: any supernatural being worshipped as controlling some part
         of the world or some aspect of life or who is the
         personification of a force [syn: deity, divinity,
         god, immortal]

Moby Thesaurus II by Grady Ward, 1.0:

304 Moby Thesaurus words for "deity":
   Aides, Aidoneus, Amen-Ra, Amor, Aphrodite, Apollo,
   Apollo Musagetes, Ares, Artemis, Ashtoreth, Astarte, Astraea,
   Athena, Atropos, Baal, Bellona, Bragi, Cailleac, Calliope,
   Castilian Spring, Cerberus, Ceres, Charon, Clio, Clotho, Cora,
   Cupid, Cynthia, Dame Fortune, Davy, Davy Jones, Decuma, Demeter,
   Despoina, Diana, Dike, Dionysos, Dionysus, Dis, Dis pater,
   Discordia, Donar, Dylan, Earth, Enyo, Erato, Erebus, Eris, Eros,
   Euterpe, Fata, Fates, Faunus, Flora, Fortuna, Frey, Freya, Frigg,
   Gaea, Gaia, Ge, Hades, Heaven, Hecate, Hekate, Hel, Helicon,
   Helios, Hera, Hermes, Hestia, Hippocrene, Hymen, Hyperion, Indra,
   Isis, Juno, Jupiter Fidius, Jupiter Fulgur, Jupiter Pluvius,
   Jupiter Tonans, Justice, Justitia, Kama, Kore, Lachesis, Loki,
   Love, Luna, Mars, Melpomene, Mercury, Minerva, Minos, Moirai,
   Morta, Muse, Nemesis, Neptune, Nereid, Nereus, Nona, Norns,
   Oceanid, Oceanus, Odin, Orcus, Osiris, Pan, Parcae, Parnassus,
   Persephassa, Persephone, Phoebe, Phoebus, Phoebus Apollo,
   Pierian Spring, Pierides, Pluto, Polyhymnia, Pomona, Poseidon,
   Priapus, Pronuba, Proserpina, Proserpine, Providence, Ra,
   Rhadamanthus, Satan, Savitar, Selene, Set, Shamash, Skuld, Sol,
   Surya, Teleia, Tellus, Terpsichore, Terra, Thalia, Themis, Thetis,
   Thor, Titan, Tiu, Triptolemos, Triptolemus, Triton, Tyche, Typhon,
   Tyr, Urdur, Varuna, Vayu, Venus, Verthandi, Vesta, Vidar, Vitharr,
   Weird Sisters, Weirds, Woden, Wotan, Zephyr, Zephyrus, Zeus,
   afflatus, artistic imagination, ball lightning, biosphere,
   blindfolded Justice, bolt, bolt of lightning, chain lightning,
   clash, clashing, commercialism, conception, conflict, contention,
   corn god, corn spirit, creative imagination, creative power,
   creative thought, creator, dark lightning, deep, demigod,
   demigoddess, disaccord, disaffinity, discord, discordance,
   discordancy, disharmony, dread rattling thunder, enmity,
   esemplastic imagination, esemplastic power, faun, fertility god,
   field spirit, fire of genius, fireball, firebolt, flying flame,
   forest god, forked lightning, fresh-water nymph, friction,
   fulguration, fulmination, genius, geography, geosphere, globe, god,
   goddess, hero, heroine, idol, incompatibility, incompatibleness,
   industrialism, inharmoniousness, inharmony, inspiration, jangle,
   jar, kelpie, lares and penates, levin bolt, lightning, limniad,
   man fish, mercantilism, mermaid, merman, mischief, mother earth,
   muse, mythicization, mythification, mythopoeia, naiad, nix, nixie,
   noncooperation, oak-cleaving thunderbolts, ocean nymph,
   open conflict, panisc, panisca, paniscus, peal of thunder, phoenix,
   poesy, poetic genius, poetic imagination, rub, satyr, sea devil,
   sea god, sea nymph, sea-maid, sea-maiden, seaman,
   shaping imagination, sheet lightning, silenus, siren,
   strained relations, stroke of lightning, sylvan deity, tension,
   terra, terrestrial globe, the Muses, the blue planet, the goat god,
   this pendent world, thunder, thunderball, thunderbolt, thunderclap,
   thundercrack, thundering, thunderpeal, thunderstorm, thunderstroke,
   undine, unharmoniousness, unpleasantness, vale, vale of tears,
   vegetation spirit, water god, water spirit, water sprite,
   whole wide world, world