Disillusioned means disappointed at finding something was not as believed. Grow disillusioned, disillusioned with politics, thoroughly disillusioned.
It says the belief was false rather than the outcome unlucky, which is what separates it from disappointed. Being disillusioned is a gain in truth and a loss in comfort at the same time.
1adjectivedisillusionedDisappointed at finding something was not as believed.
“After years of broken promises, many voters have become disillusioned with politics.”
disillusioned is a state.
From disillusion + -ed.
Etymology from Wiktionary, CC BY-SA