breaststrap vs chestplate

breaststrap

noun
  • A piece of horse tack for preventing the saddle from slipping backwards. 

  • An oblong application supporting the mammaries of a human female 

chestplate

noun
  • A plate of armor to protect a person's chest. 

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