C1 noun /ˌdɪs.ɪˈluː.ʒən.mənt/
disillusionment
désillusion
Meaning
A feeling of disappointment resulting from the discovery that something is not as good as one believed it to be.
Example
Many people experience disillusionment after unrealistic expectations.
Beaucoup de gens ressentent de la désillusion après des attentes irréalistes.