a layman
Examples
That I am a monk and you are a layman is of no importance ... rather that we are both in the light of the Holy Spirit ... Acquire peace, and thousands around you will be saved.
Outside his own ever-narrowing field of specialization, a scientist is a layman. What members of an academy of science have in common is a certain form of semiparasitic living.
I'm a bit of a layman physics junkie. I don't really understand it, but I love trying to understand it.
I am a layman in matters of culture; I would like to study them, but have only just begun to do so.
If you are not a psychiatrist, stay away from idiots. They are too stupid to pay a layman for his company.