1. past tense of undo; reversed or canceled something that was done
2. unfastened or opened something that was fastened or closed
3. caused the ruin or downfall of someone or something

Examples

• She undid all the progress we had made on the project.
• He undid his tie after the long meeting.
• The scandal undid his political career.
• I undid the knot in the rope.
• The new evidence undid the prosecution’s case.
• She carefully undid the package wrapping.
• His careless mistake undid years of careful planning.