chinstrap vs throatlatch

chinstrap

noun
  • A band of colour below a bird's mouth, resembling the chinstrap of a helmet. 

  • A form of beard that follows the jawline but does not cover the rest of the chin. 

  • A strip of leather or material used to fasten a hat or helmet under the chin. 

throatlatch

noun
  • Part of a horse's bridle that prevents the bridle from coming off over the horse's head. 

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