دیوانه 用英语:

She’s a complete lunatic.

This is a lunatic suggestion.

That guy's a real lunatic- be careful of him. Who knows what he'll do.

Watch out for the lunatics on the road.

It has been said that a man at ten is an animal, at twenty a lunatic, at thirty a failure, at forty a fraud, and at fifty a criminal.

With such a vivid imagination he'll become either a world-famous novelist or a lunatic.