prong vs sprocket

prong

noun
  • A thin, pointed, projecting part, as of an antler or a fork or similar tool. A tine. 

  • The penis. 

  • A branch; a fork. 

verb
  • To pierce or poke with, or as if with, a prong. 

sprocket

noun
  • A toothed wheel that enmeshes with a chain or other perforated band. 

  • The tooth of such a wheel. 

  • A placeholder name for an unnamed, unspecified, or hypothetical manufactured good or product. 

  • A flared extension at the base of a sloped roof. 

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