envelopment vs investment

envelopment

noun
  • 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. 

  • The act of enveloping. 

  • 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. 

investment

noun
  • The act of surrounding, blocking up, or besieging by an armed force, or the state of being so surrounded. 

  • The act of investing, or state of being invested. 

  • A placement of capital in expectation of deriving income or profit from its use or appreciation. 

  • A mixture of silica sand and plaster which, by surrounding a wax pattern, creates a negative mold of the form used for casting, among other metals, bronze. 

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