/ Dictionary / Index M Mercer Island: Meaning and Definition of Find definitions for: Mer'cer Is'land Pronunciation: [key] a city in W central Washington, on Mercer Island in Lake Washington, east of Seattle. 21,522. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mercer mercerize Related Content Daily Word Quiz: supercilious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language