1a : speech or conduct not natural to oneself : an unnatural form of behavior meant especially to impress others His French accent is just an affectation.

What is the origin of the word affectation?

affectation (n.)

"studied display, artificiality of manner or conduct," 1540s, from French affectation (16c.) or directly from Latin affectationem (nominative affectatio) "a striving after, a claiming," noun of action from past-participle stem of affectare "to strive for" (see affect (v. 2)).

What is the difference between affection and affectation?

Affection means "a feeling of liking and caring for something" and stems from the sense of affect meaning "to produce an effect on." Affectation on the other hand means "speech or conduct not natural to oneself" and is related to a different sense of affect meaning "to put a presence on" or "to posture."