/ Dictionary / Index C C.A.S.: Meaning and Definition of Find definitions for: C.A.S. Pronunciation: [key] Certificate of Advanced Studies. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cas (Thesaurus) caryopsis casa Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language