/ Dictionary / Index A A.C.S.: Meaning and Definition of Find definitions for: A.C.S. Pronunciation: [key] Advanced Communications System. American Cancer Society. American Chemical Society. American College of Surgeons. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: acs (Thesaurus) acrylyl group A.C.S.C., Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language