He's a model professional.
1)He works as a fashion model.
2)He's a professional(though we're not sure of what exactly he does for a living), and he's outstanding in his working field(like, "he's a model student")
Which way to understand the sentence is correct? I'm so confused. Is it an intrinsically vague expression that we should avoid using? Thanks for explaining.
It's 2. If you wanted the first meaning, you'd say 'professional model'.