dead-end vs loosen

dead-end

verb
  • To come to a dead-end. 

adj
  • Going nowhere; blocked. 

noun
  • A road with no exit. 

  • A position that offers no hope of progress. 

loosen

verb
  • To make loose. 

  • To free from restraint; to set at liberty. 

  • To become unfastened or undone. 

  • To relieve (the bowels) from constipation; to promote defecation. 

  • To become loose. 

  • To disengage (a device that restrains). 

How often have the words dead-end and loosen occurred in a corpus of books? (source: Google Ngram Viewer )