/ Dictionary / Index M Mersey: Meaning and Definition of Find definitions for: Mer•sey Pronunciation: (mûr'zē), [key] — n. a river in W England, flowing W from Derbyshire to the Irish Sea. 70 mi. (115 km) long. a river in SW Nova Scotia, in SE Canada, flowing SE to the Atlantic Ocean. ab. 25 mi. (40 km) long. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mersenne number Merseyside 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