cloak vs cover-up

cloak

noun
  • That which conceals; a disguise or pretext. 

  • A long outer garment worn over the shoulders covering the back; a cape, often with a hood. 

  • A blanket-like covering, often metaphorical. 

  • A text replacement for an IRC user's hostname or IP address, making the user less identifiable. 

verb
  • To cover up, hide or conceal. 

  • To render or become invisible via futuristic technology. 

  • To cover as with a cloak. 

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 cloak and cover-up occurred in a corpus of books? (source: Google Ngram Viewer )