impostor syndrome UK /ɪmˈpɒstə ˈsɪndɹəʊm/US /ɪmˈpɑstɚ ˈsɪndɹoʊm/ noun1 •A psychological phenomenon in which a person is unable to internalize their accomplishments, remaining convinced that they do not deserve any accompanying success.The office family is not the only phenomenon to watch out for at work. Another common psychological pitfall is something called the "impostor syndrome." — 1984 formsimpostor syndromes