backset vs whammy

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. 

whammy

noun
  • a serious or devastating setback 

  • an evil spell; a curse or hex 

  • the vibrato system of an electric guitar, or just its lever (whammy bar) 

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