Where the law is concerned, I am only a layman.

谈到法律，我不过是门外汉。

《新英汉大辞典》

youdao

He is a layman in economics.

他对经济学一窍不通。

youdao

"The user friendliness on the IPhone is unbelievable. It's like even a layman can use it."

VOA: standard.2010.06.25

It's hard for me as a layman to believe that even 70 is enough.

NPR: New Orleans Courts Come Back to Life

In 1998, Hawking published "A Brief History of Time, " a layman's guide to the origins of the universe.

CNN: Ask Stephen Hawking a space question

I'm just a layman in making that observation, but I think it's true.

WHITEHOUSE: Press Briefing