clavis vs kay

clavis

noun
  • A Roman key. 

  • A key; an identification guide; a series of logically organized groups of discriminating information which aims to allow the user to correctly identify a taxon. 

  • A glossary. 

  • A device for restraint of the hands. 

kay

noun
  • The name of the Latin-script letter K. 

  • A thousand of some unit (from kilo-). 

  • A kilometer. 

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