Dutch oven vs pipkin

Dutch oven

noun
  • A large metal cooking pot with a tight-fitting lid. 

  • The very end of a Dutch Masters cigar that has been rerolled with marijuana. 

  • A portable oven consisting of a metal box, with shelves, placed before an open fire. 

  • A protective cover for electrical contacts on a railway coupler, particularly but not exclusively used on the London Underground. 

  • The situation where a person breaks wind under the bedcovers, sometimes pulling them over a bedmate's head as a prank. 

  • Used other than figuratively or idiomatically: see Dutch, oven. 

  • A room or vehicle full of marijuana smoke. 

verb
  • To break wind beneath one's bedcovers or some other enclosed space. 

pipkin

noun
  • A small earthen pot. 

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