dairy cow vs milker

dairy cow

noun
  • A cow bred for the ability to produce large quantities of milk, from which dairy products are made. 

  • A black-and-white varietal of the Porcellio laevis woodlouse. 

milker

noun
  • An animal, such as a dairy cow, kept for the milk it produces. 

  • A woman’s breast. 

  • A milking machine. 

  • A person who milks. 

  • A conservative poker player who only raises the stakes on a good hand. 

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