/ Dictionary / Index C Callistus I: Meaning and Definition of Find definitions for: Cal•lis•tus I Pronunciation: (ku-lis'tus). [key] See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Callisto Callistus II 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