/ Dictionary / Index T thecium: Meaning and Definition of Find definitions for: the•ci•um Pronunciation: (thē'shē-um, -sē-um), [key] — pl. -ci•a hymenium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thecate thecodont Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language