cop vs fireman

cop

noun
  • A police officer or prison guard. 

  • The ball of thread wound on to the spindle in a spinning machine. 

  • A roughly dome-shaped piece of armor, especially one covering the shoulder, the elbow, or the knee. 

  • A tube or quill upon which silk is wound. 

  • A merlon. 

verb
  • To steal. 

  • To adopt. 

  • To obtain, to purchase (as in drugs), to get hold of, to take. 

  • To admit, especially to a crime or wrongdoing. 

  • To earn by bad behavior. 

  • Of a pimp: to recruit a prostitute into the stable. 

  • To (be forced to) take; to receive; to shoulder; to bear, especially blame or punishment for a particular instance of wrongdoing. 

  • To see and record a railway locomotive for the first time. 

fireman

noun
  • A safety inspector in coal mines. 

  • An assistant on any locomotive, whether steam-powered or not. 

  • Someone (especially one who is male) who is skilled in the work of fighting fire. 

  • A relief pitcher (reflecting the figurative analogy of rescuing the situation). 

  • A person (originally a man) who keeps the fire going underneath a steam boiler (originally, shoveling coal by hand), particularly on a railroad locomotive or steamship. 

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