/ Dictionary / Index M margin account: Meaning and Definition of Find definitions for: mar'gin account" Pronunciation: [key] an account opened by a customer with a brokerage house in which listed securities can be purchased on margin. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. margin marginal Related Content Daily Word Quiz: winsome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language