The Collaborative International Dictionary of English v.0.48:

Titan \Ti"tan\ (t[imac]"tan), a.
   Titanic.
   [1913 Webster]

         The Titan physical difficulties of his enterprise. --I.
                                                  Taylor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

titan
    n 1: a person of exceptional importance and reputation [syn:
         colossus, behemoth, giant, heavyweight, titan]
    2: (Greek mythology) any of the primordial giant gods who ruled
       the Earth until overthrown by Zeus; the Titans were offspring
       of Uranus (Heaven) and Gaea (Earth)
    3: the largest of the satellites of Saturn; has a hazy nitrogen
       atmosphere

Moby Thesaurus II by Grady Ward, 1.0:

47 Moby Thesaurus words for "Titan":
   Amen-Ra, Antaean, Antaeus, Apollo, Atlas, Briareus, Brobdingnagian,
   Charles Atlas, Cyclops, Goliath, Helios, Herculean, Hercules,
   Hyperion, Phoebus, Phoebus Apollo, Polyphemus, Ra, Samson, Savitar,
   Shamash, Sol, Superman, Surya, Tarzan, bully, bullyboy, colossal,
   colossus, cyclopean, gargantuan, giant, gigantic, gorilla, mighty,
   monstrous, muscle man, powerhouse, stalwart, strong man,
   strong-arm man, the mighty, the strong, titanic, tough, tough guy,
   tower of strength