arris vs rand

arris

noun
  • A sharp edge or ridge formed by the intersection of two surfaces 

  • A ridge formed on the surface of flaked stone, such as a arrowhead or hand axe, as the result of the intersection of two or more flake removals. 

  • A sharp edge or ridge formed by the intersection of two curved surfaces 

  • Buttocks, arse. 

rand

noun
  • A border, edge or rim. 

  • A random number. 

  • A rocky slope, especially the area over a river valley; specifically, the Rand 

  • A single rod woven in and out of the stakes. 

  • A strip of leather used to fit the heels of a shoe. 

  • The currency of South Africa, divided into 100 cents. 

How often have the words arris and rand occurred in a corpus of books? (source: Google Ngram Viewer )