/ Dictionary / Index M metridium: Meaning and Definition of Find definitions for: me•trid•i•um Pronunciation: (mi-trid'ē-um), [key] — n. any sea anemone of the genus Metridium, common in cooler waters of the Northern Hemisphere. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. metric topology metrification Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language