the hang noun
the way something made of cloth looks when it is hanging:
e.g. That coat fits you so well - the hang is perfect.

Could you tell me what "the hang" means in this example sentence?

It means the way that the coat hangs from your shoulders.

There is another similar word, "hand," which has a specific meaning when talking about clothes. "The hand" of a garment is how it feels when you touch it. "This suede jacket has a nice hand."

Very few people will use either word unless they work in the clothing business. Most people would say "Oh, that jacket fits you so well! And it feels nice too!"