Words / A2

un-DOO/ʌnˈduː/

Undo means unfasten something, or reverse a recent action: undo a button, undo a zip, undo a mistake. Redo is do again. Open is wider. On a computer, Undo reverses the last click. Past: undid; past participle: undone. Do not write undo when you mean under, or undue (too much — later).

Meaning

To open something that was fastened, or to reverse something you have just done.

Examples

• “Can you undo this zip for me?”
• “Undo the top button if the collar is tight.”
• “I undid the last change and typed the email again.”

Good to know

undo a button / zip. Computer: Undo. Past: undid / undone. Mix-up: under.

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