shorten vs unravel

shorten

verb
  • To take in the slack of (a rope). 

  • To reduce or diminish in amount, quantity, or extent; to lessen. 

  • To reduce (sail) by taking it in. 

  • To become shorter. 

  • To make shorter; to abbreviate. 

  • To make short or friable, as pastry, with butter, lard, etc. 

  • To make deficient (as to); to deprive (of). 

unravel

verb
  • To clear from complication or difficulty; to unfold; to solve. 

  • To separate the threads (of); disentangle. 

  • To become separated; (of something woven, knitted, etc.) to come apart. 

  • To separate the connected or united parts of; to throw into disorder; to confuse. 

  • To become undone; to collapse. 

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