bobbing vs skiving

bobbing

noun
  • The motion of something that bobs. 

skiving

noun
  • A type of machining that skives metal, with various applications including gear cutting. 

  • A piece made in skiving (paring or splitting) leather, especially the part from the inner, or flesh, side. 

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