osselet
/ˈɒs(ə)lɪt/noun
1 Zoology and Anatomy. Originally: any of the small bones of the carpus or tarsus of a horse. Later also: any of various other types of small bone or ossicle. Now rare or historical.
2In plural A game like knuckle-bones or jacks, played with the carpal or tarsal bones of a quadruped (or objects of similar size). rare.
3 Veterinary Med. A hard or bony growth on a joint of a horse; specifically such a growth on the fetlock. Also (in plural): the condition of having such a growth or growths; periostitis in the region of the fetlock.
Origin
Late 17th century. From French osselet small bone, kind of game, swelling of the fetlock, internal bone of a fossil cephalopod from classical Latin oss-, os bone + French -let.