/ Dictionary / Index M marine league: Meaning and Definition of Find definitions for: marine' league' Pronunciation: [key] a unit of 3 nautical miles (5.6 km). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. marine ivy mariner Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language