impostor syndromenoun [ U ]
uk/ɪmˈpɒs.tə ˌsɪn.drəʊm//ɪmˈpɑː.stɚ ˌsɪn.droʊm/the feeling that your achievements are not real or that you do not deserve praise or success:
Students from working-class backgrounds often suffer from impostor syndrome, a deep-seated sense that the world of high culture is not for them.