infix vs interpolate

infix

verb
  • To insert a morpheme inside an existing word. 

  • To instill. 

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. 

interpolate

verb
  • To introduce (something) between other things; especially to insert (possibly spurious) words into a text. 

  • During the course of processing some data, and in response to a directive in that data, to fetch data from a different source and process it in-line along with the original data. 

  • To estimate the value of a function between two tabulated points. 

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