backset vs disappointment

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. 

disappointment

noun
  • Something or someone that disappoints: that which causes disappointment. 

  • An example or the act of disappointing: a circumstance in which a positive expectation is not achieved. 

  • The feeling or state of being disappointed: a feeling of sadness or frustration when something is not as good as one hoped or expected, or when something bad unexpectedly happens. 

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