big cat vs domestic cat

big cat

noun
  • Any large feline animal, especially one of the Panthera genus, including tigers, lions, jaguars and leopards. 

  • Used other than figuratively or idiomatically: see big, cat. 

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. 

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