Mare Vaporum

[vey-pawr-uh m, -pohr-]

noun

(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).

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019