/ Dictionary / Index T -tious: Meaning and Definition of Find definitions for: -tious Pronunciation: [key] a suffix originally occurring in adjectives borrowed from Latin (fictitious); on this model, used with stems of other origin (bumptious). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. -tion tip Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language