expert vs prat

expert

noun
  • A player ranking just below master. 

  • A person with extensive knowledge or ability in a given subject. 

adj
  • Extraordinarily capable or knowledgeable. 

  • Characteristic of an expert. 

prat

noun
  • A cunning or mischievous trick; a prank, a joke. 

  • The female genitals. 

  • A fool. 

  • A buttock, or the buttocks; a person's bottom. 

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