entrench vs infix

entrench

verb
  • To cut in; to furrow; to make trenches in or upon. 

  • To surround or provide with a trench, especially for defense; to dig in. 

  • To establish a substantial position in business, politics, etc. 

  • To dig or excavate a trench; to trench. 

  • To invade; to encroach; to infringe or trespass; to enter on, and take possession of, that which belongs to another; usually followed by on or upon. 

  • To become completely absorbed in and fully accept one's beliefs, even in the face of evidence against it and refusing to be reasoned with. 

infix

verb
  • To instill. 

  • To insert a morpheme inside an existing word. 

noun
  • A morpheme that always appears between other morphemes in a word, such as -i- and -o- in English (i.e. an interfix). 

  • A morpheme inserted inside an existing word, such as -bloody- in English. 

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