debouchment vs unburdening

debouchment

noun
  • The act, or the result of debouching 

  • The point of debouch of a watercourse 

  • Opening or emptying into another part 

unburdening

noun
  • The act by which one unburdens oneself. 

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