capitulum vs nub

capitulum

noun
  • A small protuberance on a bone which articulates into another bone to form a ball-and-socket joint. 

  • The head-like mouthpart apparatus of a tick, including the palpi, mandibles, and hypostome. 

  • A densely clustered inflorescence composed of a large number of individual florets arising from a platform-like base. 

nub

noun
  • A small lump or knob. 

  • a pointing stick 

  • The clitoris. 

  • The essence or core of an issue, argument etc. 

verb
  • To push; to nudge. 

  • To beckon. 

  • To hit the ball weakly. 

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