/ Dictionary / Index E ex off.: Meaning and Definition of Find definitions for: ex off. Pronunciation: [key] ex officio. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. exoerythrocytic ex officio Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language