Board Thread:Speculation House/@comment-12443850-20130808003319/@comment-5130342-20130915150329

A titan (lowercase) is defined as "a person or thing of enormous size, strength, power, influence, etc". Which is basically what a giant is.

A Titan (uppercase) is defined as a being in Classical Mythology:

a. any of the sons of Uranus and Gaea, including Coeus, Crius, Cronus, Hyperion, Iapetus, and Oceanus.

b. any of the sisters of these, including Mnemosyne, Phoebe, Rhea, Tethys, Themis, and Thia (think Titaness).

c. any of the offspring of the children of Uranus and Gaea.

Of course, there's always the anime definition (look up Shingeki no Kyojin, a.k.a. Attack on Titan).