mantis vs nun

mantis

noun
  • A green colour, like that of many mantises. 

  • Any of various large insects of the order Mantodea that catch insects or other small animals with their powerful forelegs. 

nun

noun
  • A kind of pigeon with the feathers on its head like the hood of a nun. 

  • A member of a similar female community in other confessions. 

  • A member of a Christian religious community of women who live by certain vows and usually wear a habit, (Roman Catholicism, specifically) those living together in a cloister. 

  • The fourteenth letter of many Semitic alphabets/abjads (Phoenician, Aramaic, Hebrew, Syriac, Arabic and others). 

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