mandible vs toenail

mandible

noun
  • One of the anterior pair of mouthparts of an arthropod, designed for holding and cutting food. 

  • Any of various invertebrate mouthparts serving to hold or bite food materials. 

  • The jaw or a jawbone, especially the lower jawbone in mammals and fishes. 

  • Either of the upper and lower segments of a bird's beak. 

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 mandible and toenail occurred in a corpus of books? (source: Google Ngram Viewer )