Undoing is a defense mechanism in which a person tries to cancel out or remove an unhealthy, destructive or otherwise threatening thought or action by engaging in contrary behavior. For example, after thinking about being violent with someone, one would then be overly nice or accommodating to them.

What is the meaning of undoing?

1 : an act of loosening : unfastening. 2 : ruin also : a cause of ruin greed was to prove his undoing.

What is the meaning of undoing as it is used in a sentence?

(ʌnduɪŋ ) singular noun. If something is someone's undoing, it is the cause of their failure. His lack of experience may prove to be his undoing.