undo the knot
undo the damage
undo the mistake
A: Did you undo the package yet?
A：你把包裹拆开了吗？
B: Yes, I undid it a moment ago.
B：拆开了，我刚才拆开的。
1) undo 的过去式
2) 解开，拆开
3) 撤销，消除
1. 解开，松开
2. 撤销，使失效
verb
1. the past tense of undo; to reverse the effects of something or to unfasten something
Synonym: reverse, unfasten