/ Dictionary / Index M Marcion: Meaning and Definition of Find definitions for: Mar•cion Pronunciation: (mär'shun, -shē-un, -sē-un), [key] — n. a.d.c100–c160, Christian Gnostic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Marcie Marcionism 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