operant vs peon

operant

noun
  • An operative person or thing. 

  • Any of a class of behaviors that produce consequences by operating (i.e., acting) upon the environment. 

adj
  • That operates to produce an effect. 

peon

noun
  • A person of low rank or importance. 

  • A messenger, foot soldier, or native policeman. 

  • A lowly person; a peasant or serf; a labourer who is obliged to do menial work. 

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