pincer vs ungula

pincer

noun
  • Any object that resembles one half of a pair of pincers. 

verb
  • To surround with a pincer attack. 

ungula

noun
  • A hoof, claw, or talon. 

  • A section of a cylinder, cone, or other solid of revolution, cut off by a plane oblique to the base; so called from its resemblance to the hoof of a horse. [[File:Ungula (PSF).png|thumb|]] 

  • A surgical instrument for use in removing a dead fetus. 

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