/ Dictionary / Index M Mare Vaporum: Meaning and Definition of Find definitions for: Ma're Va•po'rum Pronunciation: (vā-pôr'um, -pōr'-), [key] (Sea of Vapors) a dark plain in the first quadrant and near the center of the face of the moon: about 39,000 sq. mi. (101,000 sq. km). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mare Undarum marezzo 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