Here is a context clues worksheet on the verb disillusion; it’s used only transitively, so don’t forget your direct object: you must disillusion someone. This word means, simply, “to free from illusion” or “to cause to lose naive faith and trust,” which is the meaning the context in the sentences in these worksheets implies–so students should infer that.
Incidentally, I don’t know about you, but I have always been circumspect about disillusioning students. It seems like a big responsibility that should be accepted carefully.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.