N-COUNT
外行；门外汉
A layman is a person who is not trained, qualified, or experienced in a particular subject or activity.
例句
The mere mention of the words 'heart failure', can conjure up, to the layman, the prospect of imminent death...
一提“心脏衰竭”四字，外行人就联想到命不久矣的情景。
There are basically two types called, in layman's terms, blue and white asbestos.
基本上有两种，用外行话说就是青石棉和白石棉。