"quack" meaning in this contex

Question

In painting and gemmary, Fortunato, like his countrymen, was a quack but in the matter of old wines he was sincere.

Answer 1

آدم متظاهر، آدم شارلاتان، کسی که به دروغ وانمود میکنه در رشته خاصی تبحر داره.