device vs smokescreen

device

noun
  • An improvised explosive device, home-made bomb 

  • A peripheral device; an item of hardware. 

  • A technique that an author or speaker uses to evoke an emotional response in the audience; a rhetorical device. 

  • An image used in whole or in part as a trademark or service mark. 

  • A motto, emblem, or other mark used to distinguish the bearer from others. A device differs from a badge or cognizance primarily as it is a personal distinction, and not a badge borne by members of the same house successively. 

  • A project or scheme, often designed to deceive; a stratagem; an artifice. 

  • Any piece of equipment made for a particular purpose, especially a mechanical or electrical one. 

  • An image or logo denoting official or proprietary authority or provenience. 

smokescreen

noun
  • Smoke used as a disguise, mask or cover, as of troops in battle. 

  • Anything used metaphorically to conceal or distract. 

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