/ Dictionary / Index C civil day: Meaning and Definition of Find definitions for: civ'il day' Pronunciation: [key] — Astron. Astron. day (def. 3c). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Civil Air Patrol civil defense Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language