set off vs walk off

set off

verb
  • To leave; to begin a journey or trip. 

  • To put into an angry mood; to start (a person) ranting or sulking, etc. 

  • To enhance by emphasizing differences. 

  • To offset, to compensate for: to reduce the effect of, by having a contrary effect. 

  • To deface or soil the next sheet; said of the ink on a freshly printed sheet, when another sheet comes in contact with it before it has had time to dry. 

  • To begin; to cause; to initiate. 

  • To cause to explode, let off. 

walk off

verb
  • To flee or abandon. 

  • To measure a distance by walking, as by counting paces or extending a measuring tape or rope. 

  • To recover from (a minor injury) or digest (a large meal) by walking around. 

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