furl vs pin down

furl

verb
  • To lower, roll up and secure (something, such as a sail or flag) 

pin down

verb
  • To attach or secure with pins. 

  • To hold the opponent back-first so both his or her shoulders touch the mat or ground. 

  • To identify something (e.g. a decision or plan) clearly or specifically. 

  • To corner somebody in order to get a firm answer. 

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