话匣子 - Chinese Idiom

话匣子

Literally means:

gramophone; radio

Actually means:

chatterbox

匣子, a box. The gramophone or the radio was called huaxiazi scores of years ago.

It figuratively means the mouth, especially someone who talks a lot. Often in collocation with dakai to form a phrase meaning "beginning to speak".

匣子，盒子。旧时指留声机或收音机。

说话的嘴巴，特别是爱说话的人。常跟“打开”搭配，表示开始说话或开口说话。