barn dance vs copulate

barn dance

verb
  • To take part in barn dancing. 

noun
  • A type of set step routine dancing, such as square dance. 

copulate

verb
  • To engage in sexual intercourse. 

adj
  • Joining subject and predicate; copulative. 

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