What does undo mean in English?

You can learn undo Pronunciation, Grammar & Synonyms in this most authoritative English Dictionary.

undo Meaning, Definition, Pronunciation, Grammar & Synonyms❤️

0 to unfasten something that is fastened or tied:
- Can someone help me to undo my seat belt?
1 to remove the good or bad effects of an action or several actions:
- I did a really tough aerobics class and then went out for dinner and undid (all) the good work!
- It's very difficult to undo the damage that's caused by inadequate parenting in a child's early years.
2 to unfasten something that is closed or tied:
- He undid the top button of his shirt and loosened his tie.
3 to remove the effects of something that happened earlier:
- It’s difficult to undo the damage caused by a father who abandons his child.

I undid the buttons on my blouse.
He had eaten so much that he had to undo his belt a couple of notches.
He had undone the buttons of his shirt, exposing an unsightly expanse of white flesh.
If the curtains are too short you could undo the hem to make them a bit longer.
He gently began to undo the zip at the back of her dress.
As noted during the example, our experience has confirmed the need for a secure and convenient way of undoing earlier transformation steps.
The sequence of transformation copies the value into the argument of amb, then performs (amb-c) and finally undoes the copying step.
Revisions of national laws may be undoing the codification of the agencies' influence just as the new international standards for banking are poised to magnify the effects of credit ratings.