Hello!Will you help me?

It means that he has an appearance or mannerisms which make him seem important or attractive.

You might say: "He has an air of authority about him." That would mean that he seems to be someone in charge of things. You might say: "He has a poetic air about him." That would mean he seems to be creative and sensitive. You might say: "He has the air of a thug about him." That would mean that he seems to be violent or dangerous.

The context helps, you know. When you read something like this, give us the entire sentence or paragraph so that we are better able to help you.

It means he smells like a fart, but shouldn't.