/ Dictionary / Index A -acious: Meaning and Definition of Find definitions for: -acious Pronunciation: [key] a suffix forming adjectives that correspond to nouns ending in the suffixesandaudacious; fallacious. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. acinus Acis Related Content Daily Word Quiz: pudgy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language