operant vs pressing

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. 

pressing

noun
  • Urgent insistence. 

  • The extraction of juice from fruit using a press. 

  • A metal or plastic part made with a press. 

  • The process of improving the appearance of clothing by improving creases and removing wrinkles with a press or an iron. 

  • A phonograph record; a number of records pressed at the same time. 

  • The application of pressure by a press or other means. 

  • A memento preserved by pressing, folding, or drying between the leaves of a flat container, book, or folio. Usually done with a flower, ribbon, letter, or other soft, small keepsake. 

adj
  • Insistent, earnest, or persistent. 

  • Needing urgent attention. 

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