dis·ac·cus·tom 
(dĭs′ə-kŭstəm)
(dĭs′ə-kŭstəm)tr.v. dis·ac·cus·tomed, dis·ac·cus·tom·ing, dis·ac·cus·toms
To render (a person) unaccustomed to something to which the person has been previously accustomed; cause to break a habit.
[Middle English disacustome, from Old French desacostumer : des-, dis- + acostumer, to accustom; see ACCUSTOM.]