/ Dictionary / Index M merchant marine: Meaning and Definition of Find definitions for: mer'chant marine' Pronunciation: [key] the vessels of a nation that are engaged in commerce. the officers and crews of such vessels. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. merchantman merchant of death 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