snarl up vs unentangle

snarl up

verb
  • to entangle 

  • to become congested. 

  • To become tangled; to become entangled 

  • To block (traffic); to cause (traffic) to be congested. 

  • To put into disarray; contort; confuse; muddle up 

unentangle

verb
  • To reverse the process of entanglement 

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