gnat vs nerd

gnat

noun
  • An annoying person. 

  • Any small insect of the order Diptera, specifically within the suborder Nematocera. 

nerd

noun
  • A person who is intellectual but generally introverted. 

  • A member of a subculture revolving around intellectualism, video games, fantasy and science fiction, comic books and assorted media. 

  • One who has an intense, obsessive interest in something. 

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