/ Dictionary / Index I -ious: Meaning and Definition of Find definitions for: -ious Pronunciation: [key] variant ofadded to stems of Latin origin, often with corresponding nouns ending inatrocious; hilarious. Cf. -eous. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: -ious (Thesaurus) IOU Iowa Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language