约定俗成 (yuē dìng sú chéng)

established by popular usage (idiom); common usage agreement; customar

Character breakdown

Usage

这个手势在我们公司已经约定俗成了,大家都懂它的意思。

This gesture has become established by convention in our company; everyone knows what it means.

Zhè gè shǒu shì zài wǒ men gōng sī yǐ jīng yuē dìng sú chéng le, dà jiā dōu dǒng tā de yì si.