deadbolt vs loosen

deadbolt

verb
  • To fasten or secure with a deadbolt. 

noun
  • A kind of lock in which the bolt (moving portion) is held in position by the cylinder rather than by a spring and so cannot be retracted except by turning the cylinder. 

  • The part of the lock which is moved when the key is engaged. 

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 deadbolt and loosen occurred in a corpus of books? (source: Google Ngram Viewer )