diverge vs invaginate

diverge

verb
  • To separate, to tend into a different direction (from another line or path). 

  • To become different; to run apart; to separate; to tend into different directions. 

  • To run apart; to separate; to tend into different directions. 

  • To become different, to separate (from another line or path). 

  • Not to converge: to have no limit, or no finite limit. 

  • Both stories start out the same way, but they diverge halfway through. 

invaginate

verb
  • To turn or fold inwardly. 

  • To fold inward to create a hollow space where none had existed, as with a gastrula forming from a blastula. 

  • To fold up or enclose into a sheath-like or pouch-like structure, either naturally or as part of a surgical procedure. 

adj
  • Having one portion of a hollow organ drawn back within another portion. 

  • sheathed 

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