burl vs nub

burl

noun
  • A knot or lump in thread or cloth. 

  • Wood of a mottled veneer, usually cut from such a growth. 

  • A tree growth in which the grain has grown in a deformed manner; a burr knot. 

verb
  • To remove the knots in cloth. 

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 burl and nub occurred in a corpus of books? (source: Google Ngram Viewer )