concealment vs cover-up

concealment

noun
  • The condition of being hidden or concealed. 

  • The practice of keeping secrets. 

  • protection from observation or surveillance. 

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. 

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