To free from illusion or false ideas; disenchant
To free from a falsehood or misconception:
To give knowledge of something to; tell; acquaint with a fact, etc.
Find another word for undeceive. In this page you can discover 6 synonyms, antonyms, idiomatic expressions, and related words for undeceive, like: disillusion, disabuse, set right, inform, correct and deceive.