Pseudo is something or someone fake trying to pass as the real thing — a fraud or impostor.
Pseudo can be a person who is a faker, but it's usually a prefix. For example, a pseudo-intellectual is trying to convince you he has a great, educated mind, even though he doesn't. A pseudo-celebrity isn't really very famous. You can buy pseudo-Chanel bags from shifty sidewalk vendors: another name for them might be rip-offs. They look like the real thing but aren't, though they don't cost as much either. Anything pseudo isn't real or genuine.