backset vs mix up

backset

noun
  • A check; a relapse; a discouragement; a setback. 

  • Whatever is thrown back in its course, such as water. 

verb
  • To plow again in the fall; said of prairie land broken up in the spring. 

mix up

noun
  • A confusion or reversal. 

  • A mix, blend, or variety. 

verb
  • To become involved with, especially socially or romantically. 

  • To confuse or reverse. 

  • To prepare something from ingredients that are mixed. 

  • To shuffle. 

  • To combine thoroughly. 

  • To mix or blend thoroughly and completely. 

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