impregnate vs lavage

impregnate

verb
  • To fill pores or spaces with a substance. 

  • To saturate, or infuse. 

  • To fertilize. 

  • To cause to become pregnant. 

lavage

verb
  • To wash a hollow organ 

noun
  • A washing. 

  • A washing of a hollow organ. 

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