Meaning of Mare Imbrium

Ma're Im'bri•um

Pronunciation: (im'brē-um), [key]
  1. (Sea of Showers) a dark plain in the second quadrant of the face of the moon: about 340,000 sq. mi. (880,000 sq. km).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.