nail down vs toenail

nail down

verb
  • to attach with nails 

  • to make something (e.g. a decision or plan) firm or certain 

toenail

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

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

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