un ‧ learn /ʌnˈlɜːn $ -ɜːrn/ BrE AmE verb ( past tense and past participle unlearned or unlearnt /-ˈlɜːnt $ -ˈlɜːrnt/) [transitive]
informal to deliberately forget something you have learned, in order to change the way you do something:
It’s difficult to unlearn bad driving habits.