The Collaborative International Dictionary of English v.0.48:

Phoebus \Ph[oe]"bus\ (f[=e]"b[u^]s), n. [L., fr. Gr. Foi^bos,
   fr. foi^bos pure, bright.]
   1. (Class. Myth.) Apollo; the sun god.
      [1913 Webster]

   2. The sun. "Ph[oe]bus 'gins arise." --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Phoebus
    n 1: (Greek mythology) Greek god of light; god of prophecy and
         poetry and music and healing; son of Zeus and Leto; twin
         brother of Artemis [syn: Apollo, Phoebus, Phoebus
         Apollo]

Moby Thesaurus II by Grady Ward, 1.0:

77 Moby Thesaurus words for "Phoebus":
   Agdistis, Amen-Ra, Amor, Aphrodite, Apollo, Apollon, Ares, Artemis,
   Ate, Athena, Bacchus, 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 Apollo, Pluto, Poseidon, Proserpina,
   Proserpine, Ra, Rhea, Saturn, Savitar, Shamash, Sol, Surya, Tellus,
   Titan, Venus, Vesta, Vulcan, Zeus