inflection vs spiracle

inflection

noun
  • Diffraction. 

  • Change in the form of a word (morphologic change) to express different grammatical categories. 

  • Any form produced by such an instance of a change, such as the principal parts for any given stem: any of the declined or conjugated forms that constitute its declension or conjugation. 

  • An affix representing such an instance. 

  • A turning away from a straight course. 

  • A change in curvature from concave to convex or from convex to concave. 

  • A change in pitch or tone of voice. 

  • An instance of such change. 

spiracle

noun
  • Any small aperture or vent for air or other fluid. 

  • A pore or opening used (especially by arthropods and some fish) for respiration. 

  • The blowhole of a whale, dolphin or other similar species. 

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