Manqué
Manqué (feminine, manquée) is a term used in reference to a person who has failed to live up to a specific expectation or ambition. It is usually used in combination with a profession: for example, a career civil servant with political prowess who nonetheless never attained political office might be described as a "politician manqué". It can also be used relative to a specific role model; a second-rate method actor might be referred to as a "Marlon Brando manqué".