envelopment vs insertion

envelopment

noun
  • The act of enveloping. 

  • An offensive action in which an attacking force moves over or around the enemy and attacks from the rear; see also pincer movement. 

  • That which envelops; a covering. 

  • An action to seize the opponent's blade in one line and lead it (without losing contact) through a full circle to end in the same line. 

insertion

noun
  • The act of inserting, or something inserted. 

  • With a nuclear bomb, the process of going from subcritical to prompt critical. 

  • The distal end of attachment of a muscle to a bone that will be moved by the muscle. 

  • The addition of a nucleotide to a chromosome by mutation. 

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