Poser (noun)

A person who poses or pretends to be something they are not, often in order to impress others.

Origin:

Late 18th century: from french poser "to place, put" (the original sense in english being "a person who poses for an artis.t")

Examples:

1. He was a poser and was always trying to show off his wealth and status.
2. The group didn't trust her because they suspected she was a poser and not a true member of their community.
3. He was a poser, he was always trying to fit in with the crowd.
4. She was a poser, she pretended to be someone she was not.
5. The poser was always trying to impress others with his fake stories and lies.