lookout vs spy

lookout

noun
  • A person on watch for approaching enemy, police, danger, etc. 

  • A session of watching for an approaching enemy, police, etc. 

  • A vantage point with a view of the surrounding area. 

  • A joist that extends in cantilever out from the exterior wall (or wall plate) of a building, supporting the roof sheathing and providing a nailing surface for the fascia boards. 

  • An observation window. 

  • A subject for observation; a prospect or view. 

  • One's perspective, outlook; hence, one's responsibility. (used with a possessive pronoun or a noun in a possessive form). 

spy

noun
  • A person who secretly watches and examines the actions of other individuals or organizations and gathers information on them (usually to gain an advantage). 

  • A defensive player assigned to cover an offensive backfield player man-to-man when they are expected to engage in a running play, but the offensive player does not run with the ball immediately. 

verb
  • To act as a spy. 

  • To search narrowly; to scrutinize. 

  • To explore; to see; to view; inspect and examine secretly, as a country. 

  • To spot; to catch sight of. 

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