扳ㄅㄢ指ㄓˇbānzhǐ

  1. 古代射箭時戴於拇指上的指環，用以勾弦，保護手指。多用玉石或象牙製成，後多作為裝飾用。也作「扳指兒」。例 「玉扳指」。

英ornamental thumb ring (originally a ring, often made from jade, worn by archers in ancient times to protect the right thumb when drawing a bowstring)​