/ Dictionary / Index T Thalassa: Meaning and Definition of Find definitions for: Tha•las•sa Pronunciation: (thu-las'u), [key] — n. Class. Myth. the personification of the sea. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thalamus thalassemia Related Content Daily Word Quiz: entomology Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language