1 sentence

1. “在”是构成古代自谦词“在下”的一个汉字。

   “ zài” shì gòu​chéng gǔ​dài zì​qiān cí“ zài​xià” de yī gè hàn​zì.

   The character 'zai' is part of the ancient self-deprecatory term 'zaixia'.

   Source: Dong Chinese Dictionary