disillusion

Short definition from Wiktionary

Verb

1. 1
   To free or deprive of illusion; to disenchant.

Noun

1. 1
   The act or process of disenchanting or freeing from a false belief or illusion.
2. 2
   The state of being freed from a constructed or imposed illusion; the recognition of an underlying truth previously obscured by a false or controlled narrative.