cover-up vs put-on

cover-up

noun
  • An attempt to conceal or disguise something, especially a wrongdoing or a mistake. 

  • An item of clothing to be worn over a swimsuit while not in the water. 

put-on

noun
  • A deception, hoax, or practical joke. 

How often have the words cover-up and put-on occurred in a corpus of books? (source: Google Ngram Viewer )