fetlock vs hairbrush

fetlock

noun
  • The tuft of hair that grows at this joint. 

  • A joint of the horse's leg below the knee or hock and above the hoof. 

hairbrush

noun
  • A brush used in hair care for brushing, tidying, and detangling hair 

verb
  • To spank with a hairbrush. 

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