invaginate vs untie

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 

untie

verb
  • To loosen, as something interlaced or knotted; to disengage the parts of. 

  • In the Perl programming language, to undo the process of tying, so that a variable uses default instead of custom functionality. 

  • To resolve; to unfold; to clear. 

  • To become untied or loosed. 

  • To free from fastening or from restraint; to let loose; to unbind. 

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