lunchbox vs sidekick

lunchbox

noun
  • A luggable; an early laptop computer, usually a unit with a handle and a fold-out keyboard. 

  • A simple portable transmitter sometimes used in phreaking. 

  • A lunch packaged in a disposable box to be taken away to eat. 

  • The male genitals when enclosed in clothing. 

  • A cocktail made with beer, orange juice, and almond liqueur. 

  • A container for transporting meals, especially lunch. 

sidekick

noun
  • In literature, theatre/theater, etc., a good foil of the protagonist, a character who helps emphasize the traits of the main character. 

  • An assistant to another person, especially to a superior or more important person. 

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