lip-strap
noun/lɪpstɹæp/
Etymology From lip + strap.
1
A small strap with a buckle running between the cheeks of a bit, to prevent the horse from biting on the cheek of the bit in its mouth.
- He was not a horsey man, but he liked people to believe he had been one once; and he wove fantastic stories of the hunting-bridle to which this particular lip-strap had belonged.1888, Rudyard Kipling, “Watches of the Night”, in Plain Tales from the Hills, Folio, published 2005, page 59: