bun vs duck's arse

bun

noun
  • A tight roll of hair worn at the back of the head. 

  • A drunken spree. 

  • The vagina. 

  • A newbie. 

  • A Korean unit of length equivalent to about 0.3 cm. 

  • marijuana cigarette, joint 

  • A small bread roll, often sweetened or spiced. 

  • A cupcake. 

  • A buttock. 

verb
  • To form (the hair) into a bun. 

  • To smoke cannabis. 

  • To shoot. 

duck's arse

noun
  • A hairstyle in which the hair is swept back along the sides of the head to meet in a point at the back, thus resembling the tail feathers of a duck. 

How often have the words bun and duck's arse occurred in a corpus of books? (source: Google Ngram Viewer )