operant vs predominant

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. 

predominant

noun
  • A subdominant. 

adj
  • Common or widespread; prevalent. 

  • Significant or important; dominant. 

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