dis·a·buse (dĭs′ə-byooz′)
tr.v. dis·a·bused, dis·a·bus·ing, dis·a·bus·es
To free from a falsehood or misconception: "It's up to you whether you want to disabuse your students of their fantasy that A's are guaranteed" (Rachel Kadish).
[French désabuser : dés-, dis- + abuser, to delude (from Old French, to misuse; see abuse).]