Wiktionary
n. (context astronomy geology English) An escarpment on another planet or a moon.
Wikipedia
Rupes is the Latin word for 'cliff'. It is used in planetary geology to refer to escarpments on other worlds. As of January 2013, the IAU has named 62 such features in the Solar System, on Mercury (17), Venus (7), the Moon (8), Mars (23), the asteroids Vesta (2) and Lutetia (2), and Uranus's satellites Miranda (2) and Titania (1).
How rupes formed is, as of 2008, a matter of speculation. Compressional strain from the cooling of the crust of terrestrial planets and large scale displacement due to impacts are the two dominant theories.
'''Rupes ''' was a fort in the Roman province of Dacia.
Usage examples of "rupes".
Chaldaei stupuere senes, Cumanaque rursus Itonuit rupes, rabidae delubra Sibyllae.
Eventually of course they would end up with a largish ice cap, and then part of it would pool down into the huge depression under the Promethei Rupes, another partially erased old impact basin.