He claims to be a doctor, but he's nothing but a fast-talking phoney.
disapproval If you say that someone is phoney, you disapprove of them because they are pretending to be someone that they are not in order to deceive people. He looks totally phoney to me. Phoney is also a noun. `He's false, a phoney,' Harry muttered
disapproval If you describe something as phoney, you disapprove of it because it is false rather than genuine. He'd telephoned with some phoney excuse she didn't believe for a minute
A person who professes beliefs or opinions that he or she does not hold or assumes an identity other than their own