Montes Apenninus

[mon-tuh s ap-uh-nahy-nuh s]

noun

a mountain range in the first and second quadrants of the visible face of the moon, forming the SE border of Mare Imbrium: about 600 miles (970 km) long.

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