ratchet vs serration

ratchet

noun
  • A ratchet wrench. 

  • A pawl, click, or detent for holding or propelling a ratchet wheel, or ratch, etc. 

  • A noisemaker or musical instrument where sound is generated by a board striking against a rotating gear. See gragger, raganella. 

  • A procedure or regulation that goes in one direction, usually up. 

  • A mechanism composed of a ratchet wheel, or ratch and pawl. 

adj
  • Ghetto; unseemly, indecorous. 

verb
  • To increment or decrement. 

  • To cause to become incremented or decremented. 

serration

noun
  • One of the teeth in a serrated or serrate edge. 

  • A set of teeth or notches. 

  • The state of being serrated. 

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