Meaning of “disillusionment” - Learner’s Dictionary

disillusionment

noun [ U ] uk us /ˌdɪsɪˈluːʒənmənt/ (also disillusion)

the disappointment someone feels when they discover something is not as good as they thought it was:

There's growing disillusionment with the government.

(Definition of “disillusionment” from the Cambridge Learner’s Dictionary © Cambridge University Press)