/ Dictionary / Index M market letter: Meaning and Definition of Find definitions for: mar'ket let"ter Pronunciation: [key] a publication containing information concerning market conditions, expectations, etc., esp. one produced by a securities brokerage firm or other financial organization. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. marketing market order Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language