knockabout vs operant

knockabout

noun
  • An act of playing a sport casually or informally. 

  • A worker habitually engaged in casual employment. 

  • A small sailboat lacking a bowsprit, of a type found primarily in the Massachusetts area. 

  • A person living in rough, violent conditions. 

  • A tumbler. 

  • A slapstick comedian or comedy. 

  • Clothing suitable for rough use. 

adj
  • Boisterous 

  • Suitable for rough use. 

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. 

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