/ Dictionary / Index C Calixtus I: Meaning and Definition of Find definitions for: Ca•lix•tus I Pronunciation: (ku-lik'stus), [key] — Saint, a.d. c160–222, Italian ecclesiastic: pope 218–222. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Calixtine Calixtus II Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language