扳ㄅㄢbān指ㄓˇzhǐ

  1. 古代射箭時戴於大拇指上的指環。多用玉或象骨製造，後作為裝飾品。《海上花列傳·第二一回》：「仲英套上扳指，掛上錶袋，手執摺扇。」

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)​