Pronounced jiāng shī nán, this refers to men who are knowledgeable but live in their own intellectual dream worlds. They are usually not popular among women, largely because of their introverted natures.
Let's put it into context:
Phil: Have you seen Jimmy lately? It seems that he has suddenly vanished from the world.
Allen: Well, that's not surprising to me. He is a famous jiāng shī nán, who fantasizes about living in his own dream world every day.
Phil: I'm kind of worried about him. He is a genius in some ways, and a potential scientist is hard to come by.
Allen: That's true. I also respect his scientific spirit. Maybe we should call his sister today.
Phil: Ok, let's do it.
