/koh perr"ni keuhs, keuh-/ , n.
1. Nicolaus /nik'euh lay"euhs/ , ( Mikolaj Kopernik ), 1473-1543, Polish astronomer who promulgated the now accepted theory that the earth and the other planets move around the sun ( the Copernican System) .
2. a crater in the second quadrant of the face of the moon, having an extensive ray system: about 56 mi. (90 km) in diameter from crest to crest with walls rising about 12,000 ft. (3650 m) from its floor; having several central mountains the highest being about 2400 ft. (730 m).