domestic cat vs kitty

domestic cat

noun
  • A domesticated cat, of the species Felis catus or Felis silvestris catus, especially one kept as a pet or for vermin control. 

kitty

noun
  • A pet name for a cat. 

  • In a home game, a small, specified amount taken from each pot to pay the host's expenses. 

  • A kitten or young cat. 

  • A set of additional cards dealt face down in some games. 

  • A money pool used for a particular purpose, such as for a card game or for shared expenses. 

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