copper vs spending money

copper

adj
  • Made of copper. 

  • Having the reddish-brown colour/color of copper. 

noun
  • The reddish-brown colour/color of copper. 

  • A police officer. 

  • A reddish-brown, malleable, ductile metallic element with high electrical and thermal conductivity, symbol Cu, and atomic number 29. 

  • Any of various lycaenid butterflies with copper-coloured upperwings, especially those of the genera Lycaena and Paralucia. 

verb
  • To sheathe or coat with copper. 

spending money

noun
  • A sum of cash kept in one's personal possession, for routine expenses or incidental purchases. 

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