Rima
Full definition of rima
Noun
rima
(plural rimae)- (anatomy) A cleft or gap between two symmetrical parts, particularly between the vocal folds.
- (astronomy) A crack or fissure on a lunar or planetary surface; a rille.
- 2006, What's Up 2006: 365 Days of Skywatching http://books.google.com/books?id=tLUFJ53HG8sC, page 128:Look for three prominent interior craters, as well as an ancient rima falling near the shadow's edge.