/ Dictionary / Index M Mare Humorum: Meaning and Definition of Find definitions for: Ma're Hu'mo•rum Pronunciation: (hy'mur-um, hy-môr'-, -mōr'-), [key] (Sea of Moisture) a dark plain in the third quadrant of the face of the moon: about 45,000 sq. mi. (117,000 sq. km). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mare Frigoris Mare Imbrium 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