backset vs whitewashing

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. 

whitewashing

noun
  • The effacement of errors or bad actions. 

  • The application of whitewash. 

  • The process of whitewashing, of making over (a person or character, a group, an event, etc) so that it is or seems more white (Caucasian), for example by applying makeup to a person, or by covering over the participation of people of color in an event and focusing on only white participation. 

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