The word 'undo' means to reverse or cancel something that has been done. For example, if you make a mistake while drawing, you can 'undo' it to fix it.
You pronounce 'undo' like this: un-doe. The 'un' sounds like 'un' in 'fun', and 'do' sounds like 'do' in 'do it'.
The word 'undo' comes from the Old English word 'undon', which means to reverse or take away.
The word 'undo' in Hindi is 'पूर्ववत करना' (Pūrvavat karnā).