teat vs udder

teat

noun
  • The projection of a mammary gland from which, on female mammals, milk is secreted. 

  • Synonyms: tit (now vulgar), pap, nipple, dug 

  • An artificial nipple used for bottle-feeding infants. 

  • Something resembling a teat, such as a small protuberance or nozzle. 

udder

noun
  • An organ formed of the mammary glands of female quadruped mammals, particularly ruminants such as cattle, goats, sheep and deer. 

  • A woman's breast. 

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