big toe vs toenail

big toe

noun
  • The largest toe (usually) on each human foot (i.e. the toe closest to the other foot when the feet are flat on the ground, side by side, and the legs not crossed) or on a foot of certain other animals. 

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. 

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