incarcerate vs loosen

incarcerate

verb
  • To lock away; to imprison, especially for breaking the law. 

  • To confine; to shut up or enclose; to hem in. 

loosen

verb
  • To free from restraint; to set at liberty. 

  • To make loose. 

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