toenail vs unguis

toenail

noun
  • The thin, horny, transparent plate covering the upper surface of the end of a toe. 

verb
  • To fasten two pieces of lumber together by applying nails or screws into both boards at an angle. 

unguis

noun
  • The nail, claw, talon, or hoof of a finger, toe, or other appendage. 

  • The slender base of a petal in some flowers; a claw; an ungula. 

  • An old measure equal to the length of the nail of the little finger. 

  • One of the terminal hooks on the foot of an insect. 

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