Dictionary

undo

verb un·do \ˌən-ˈdü, ˈən-\

: to open or release (something) : to unfasten or loosen (something)

: to change or stop the effect of (something)

: to cause the failure of (someone or something)

un·did\-ˈdid\un·done\-ˈdən\un·do·ing\-ˈdü-iŋ\

Full Definition of UNDO

transitive verb
1
:  to open or loose by releasing a fastening
2
:  to make of no effect or as if not done :  make null :  reverse
3
a :  to ruin the worldly means, reputation, or hopes of <a politician undone by scandal>
b :  to disturb the composure of :  upset <she's come undone>
c :  seduce 3
intransitive verb
:  to come open or apart
un·do·er \-ˈdü-ər\ noun

Examples of UNDO

  1. You can't undo the past.
  2. The damage cannot be undone.
  3. He was undone by greed.

First Known Use of UNDO

before 12th century
UNDOER Defined for Kids

undo

verb un·do \ˌən-ˈdü\
un·did \-ˈdid\un·done \-ˈdən\un·do·ing \-ˈdü-iŋ\un·does \-ˈdəz\

Definition of UNDO for Kids

1
:  untie 2, unfasten <Can you undo this knot?>
2
:  to cancel the effect of :  reverse <The damage cannot be undone.>
3
:  to cause the ruin or failure of <He was undone by greed.>

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