/ Dictionary / Index A avast: Meaning and Definition of Find definitions for: a•vast Pronunciation: (u-vast', u-väst'), [key] — imperative verb. Naut. (used as a command to stop or cease): Avast heaving! Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. avaricious avatar Related Content Daily Word Quiz: loathe Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language