dragonfly vs gnat

dragonfly

noun
  • An insect of the suborder Epiprocta or, more strictly, the infraorder Anisoptera, having four long transparent wings held perpendicular to a long body when perched. 

gnat

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

  • An annoying person. 

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