To rid (someone) of false ideas
To make or put right:
To free from illusion or false ideas; disenchant
To give knowledge of something to; tell; acquaint with a fact, etc.
To cause to believe what is not true; mislead.
Find another word for undeceive. In this page you can discover 9 synonyms, antonyms, idiomatic expressions, and related words for undeceive, like: disabuse, correct, disillusion, inform, perswade, condemne, set right, deceive and parted-from.