operant vs orderly

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. 

orderly

noun
  • A hospital attendant given a variety of non-medical duties. 

  • A soldier who carries out minor tasks for a superior officer. 

adj
  • Being on duty; keeping order; conveying orders. 

  • Neat and tidy; possessing order. 

  • Methodical or systematic. 

  • Peaceful; well-behaved. 

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