没大没小

没大没小

Literally means:

no big or little

Actually means:

show no respect for one's elders or superiors

It means one violates the Chinese social etiquettes, and does not follow the rules concerning people's seniority or hierarchy in handling interpersonal relationships. It is often used to indicate that one fails to show due respect for his elders or superiors in his speech and action.

一个人违反中国人的礼貌习俗，在处理人与人的关系时没有区分辈分的大小或地位的高低。多用来指在言行举止上表现出不尊重长辈或地位高的人。