clapper
🇺🇸
/ˈklæpər/
🇬🇧
/ˈklæpə(r)/
A small piece of metal inside a bell that strikes the bell to make it sound.
The loud sound of the church bell was caused by the rapid movement of the clapper inside.
教堂钟声之所以响亮,是因为钟内敲击器的快速运动。