unlearn
verb (used with object)
to forget or lose knowledge of.
Used to express a completed action that took place before another specific past action occurred.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Then he decided to return to his own original gait, but in the interval he had unlearnt it, and he could walk neither the one way nor the other properly.
From The Legends of the Jews — Volume 1 by Henrietta Szold