Breadcrumb Home > Dictionary > Index A aut-: Meaning and Definition of Find definitions for: aut- Pronunciation: [key] var. of before a vowel: autacoid. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Austro-Prussian War autacoid ✖ Related Content Daily Word Quiz: tendentious Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language