extravasate vs spiracle

extravasate

noun
  • That which is outside a vessel (especially blood or other bodily fluids). 

verb
  • To flow (or be forced) from a vessel. 

adj
  • Outside of a vessel. 

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 extravasate and spiracle occurred in a corpus of books? (source: Google Ngram Viewer )