early 15c., from Latin titan, from Greek titan, member of a mythological race of giants (originally six sons and six daughters of Gaia and Uranus) who were overthrown by Zeus and the other gods. The war was a popular theme for Greek artists and writers. The name is perhaps from tito "sun, day," which probably is a loan-word from a language of Asia Minor. Sense of "person or thing of enormous size or ability" first recorded 1828. Applied to planet Saturn's largest satellite in 1831; it was discovered 1655 by Dutch astronomer Christiaan Huygens, who named it Saturni Luna "moon of Saturn." Related: Titaness; titanian.
Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).
In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.