billy vs rood goose

billy

noun

  • A billy goat. 

  • A good friend. 

  • A billy club. 

  • A male goat; a ram. 

  • A slubbing or roving machine. 

  • A bong for smoking marijuana. 

  • A tin with a swing handle used to boil tea over an open fire; a billycan; a billypot. 

  • A condom. 

rood goose

noun

  • the barnacle goose. 

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