/ Dictionary / Index M Mare Fecunditatis: Meaning and Definition of Find definitions for: Ma're Fe•cun•di•ta'tis Pronunciation: (fā-koon"di-tä'tis, fē-), [key] (Sea of Fertility) a dark plain in the fourth quadrant and extending into the first quadrant of the face of the moon: about 160,000 sq. mi. (415,000 sq. km). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mare Erythraeum Mare Frigoris Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language