copilot vs gamble

copilot

verb
  • To serve as relief or assistant pilot. 

noun
  • A backup or assistant pilot of an aircraft. 

gamble

verb
  • To take a risk, with the potential of a positive outcome. 

  • To risk (something) for potential gain. 

  • To interact with equipment at a casino 

  • To play risky games, especially casino games, for monetary gain. 

noun
  • A risky venture. 

  • A bet or wager. 

  • A significant risk, undertaken with a potential gain. 

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