Affectation (noun)

1. An artificial or studied mannerism assumed in order to impress others.
2. An artificial or exaggerated display of feeling or action.

Origin:

From latin affectatio, from affectus (past participle of afficere, "to do something to") + -ion (noun-forming suffix).

Examples:

1. He spoke with such an affectation, it was clear he was trying to impress the crowd.
2. She put on an affectation of being sophisticated, but it was clear she was just trying too hard.
3. The affectation in his speech made it difficult to take him seriously.
4. His affectation of disinterest was clearly just a front.
5. The actress's affectation of a British accent was unconvincing.