/ Dictionary / Index A Acis: Meaning and Definition of Find definitions for: A•cis Pronunciation: (ā'sis), [key] — n. Class. Myth. the lover of Galatea, killed by Polyphemus out of jealousy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. -acious -acity Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language