Designers should favour allowing users to undo a delete operation over confirming it (e.g. GMail lets you undo e-mail deletion instead of asking if you are sure).

What would you call such operation in general? I have used an undoable operation term but then I realized that undoable really means an operation that can not be done.

I have came up with cancellable operation then but I feel it is not the same. Now it looks like the operation has already been started and can be interrupted by cancelling it - which is not true.

So - what would you call an operation you can undo?

We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.

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    rollback is what programmers often call this event. execution of rollback means that you are going to undo everything that you have done. on the other hand, we also have commit, with which we would permanently save the changes that we have done. – Archie Azares Jun 8 '16 at 7:48
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    But "rollback" & "commit" would not be understood by lay people. – TrevorD Jun 8 '16 at 11:22
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    Are you wanting a term understandable to lay people, or only for programmers? – TrevorD Jun 8 '16 at 11:26
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    @talrnu (Undo + able) and (Un + doable) are two origins for the word. So it has two technically correct meanings, not just one. – NVZ Jun 8 '16 at 16:44
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    In mathematics, we may use the term "invertible" for something that can be undone. – GEdgar Jun 9 '16 at 1:15

11 Answers 11


When you undo an operation in Gmail, for instance, the state of the mail program is reverted by reversing the most recent user action. Therefore, one suggestion to describe your "undo-able" set of operations is:


able to be changed back to an earlier or original state
"Fortunately, the damage is reversible."

or revertibleWiktionary

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    Also in chemistry: reversible reaction – Ben Voigt Jun 8 '16 at 22:02
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    To put this back in context: "Designers should favor operations that can be reversed over those that can merely be canceled." As OP suspects, the word "canceled" is not a good synonym for "reversed" or "undone", but it makes a good antonym for "confirmed". – Gary Botnovcan Jun 9 '16 at 5:36
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    "Reversible" has a good solid foundation in thermodynamics. "A reversible process is a process where the effects of following a thermodynamic path can be undone, without increasing entropy, by exactly reversing the path." – Jamie Hanrahan Jun 11 '16 at 4:27
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    Thank you. Finally, I have chosen the revertible because then I can say I revert the operation. I would have to reverse the operation if it was reversible. – fracz Jun 11 '16 at 11:15
  • If someone is interested in the outcome, here it is. – fracz Jun 11 '16 at 11:59

You said:

I have used an undoable operation term but then I realized that undoable really means an operation that can not be done.

Interestingly enough, quite a few online dictionaries actually mention undoable in its "can be undone" meaning — Your Dictionary, Collins, TFD, Wiktionary

In some cases the context will be able to tell which version of undoable you're using, but in others, like the one you've quoted, you'll have to use an alternative (and I think that NVZ's reversible is a nice one).

Edit after comment:

Unundoable - Yourdictionary, Wiktionary, Wordnik, Google Books

•Not undoable (unable to be undone).

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    Sweet! I will use that all the time now! – Kimball Jun 9 '16 at 10:52
  • @Kimball: Do that. You might even try a "ununundoable" as a synonym of "undoable" in its "can't be undone" meaning. I'll support you! – MadWard Jun 9 '16 at 10:56
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    Certainly in the software industry "undoable operation" means to me an operation that can be undone. – abligh Jun 9 '16 at 11:52
  • I like undoable as an answer to the O.P.'s question. As for unundoable, I think I might prefer irrevocable or permanent. – J.R. Jun 9 '16 at 22:11
  • Not reversible is much simpler to understand compare to unundoable. Double negation always get me annoyed. – Dio Phung Jun 9 '16 at 22:30

To add to the list of "re-" words:


meaning "capable of being revoked or cancelled."

This also has the neat antonym of "irrevocable" for those changes which can't be cancelled.

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    This doesn't fit the context. To cancel or revoke is not to undo, rather it's to cease doing or to stop before doing. Doesn't really fit the context of cleaning up the damages already done, e.g. undo. – FatalSleep Jun 8 '16 at 11:23
  • @FatalSleep I'm confused. Isn't your description of revoke pretty much exactly what the original poster describes? – origimbo Jun 8 '16 at 12:04
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    In that case revoke doesn't work, you can't revoke an operation that's already been completed. You can only revoke an operation that is already in action. If the operation has been completed, then it has to be undone. – FatalSleep Jun 8 '16 at 12:44
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    @MartinSmith semantically to revoke is to deny change, not to undo change. By denying change you don't allow change to take place, by undoing change you're reversing the change and the effects thereof. So it doesn't make sense to think of revoke and undo as directly interchangeable. – FatalSleep Jun 8 '16 at 16:28
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    Given that the context is in computer systems, there is a significant semantic difference between "undo" and "revoke" when you consider the state of a system. When an operation is "undone" the state of the system is reverted to the point before the operation was performed. So, if you delete some text in a Word document, then undo the delete, the text isn't re-typed, rather the state is reverted so that the deletion never happened. If I issue someone a driver's license and then revoke it, the fact is still that they had a license. If I undo it then it is as if they never held one. – Paulw11 Jun 10 '16 at 1:12

In the world of Information technology, such thing is called rollback


the act of reversing or undoing something

The word was originally use as a method in database management system (DBMS) which has been adopted by some IT professionals in the field as a general terminology in the world of Information Technology.

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    If undo is to rollback, then undoable is to what? – NVZ Jun 8 '16 at 8:23
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    Ok, but can you say rollbackable operation? I think I'm looking for an adjective here. – fracz Jun 8 '16 at 8:52
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    This answer is plain wrong, sorry. – talrnu Jun 8 '16 at 16:39
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    @talrnu Merely asserting that something is 'wrong' does not advance the issue one iota. Please explain. – TrevorD Jun 8 '16 at 16:45
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    The question explicitly asks, "what would you call an operation you can undo?". Rollback does not describe an operation you can undo, it describes an operation you can perform to undo another operation. "This action can be rolled back" is not a single word, and cannot be distilled to a short idiomatic phrase. In summary, this answer is only tangentially related to the question. – talrnu Jun 8 '16 at 17:48

In the VFX and CGI fields, we call something that you can undo "non-destructive", as in: This program lets us use a non-destructive workflow.

This is in contrast to destructive, where actions are permanent or semi-permanent. While non-destructive is common in those fields, and I believe it also sees use in programming and audio fields, it's not commonly used in regular language. However, it is a very accurate term, and in my opinion at least, is intuitive, when I first heard the term, I never had to ask what it meant.

  • That's a tangent. A non-destructive filter on an image leaves the bitmap intact, yet both a destructive and non-destructive filter could be undone. – Andrew Gallasch Jun 13 '16 at 10:28

while revertible is probably the most precise fit, reversible is a much more common word and nearly as precise.

from an etymological perspective, the word undo is unusual because the prefix "un-" generally implies that something has not been done yet (e.g. "undone", "undoable"), while "de-" or "dis-" prifix is more commonly used to indicate the reversion or removal of a trait. e.g. "unconstructed" vs "deconstructed", "uncoupled" vs "decoupled, "unproven" vs "disproven", "uninfected" vs "disinfected". so, theoretically, the word you should be seeking is "dedoable" or "disdoable", but sadly there is no precident for either word.


An interesting form that is uncommon in the general sense, but is very common in mathematics and signal processing, is linear or invertible.

If you taken an audio signal for example, and increase the volume, you can get the original signal back by decreasing the volume of the amplified signal.

However, in real world applications, if you increase the volume of a signal too much, you clip the signal, and lose information. You can't undo such an operation unless you have a copy of the original signal stored somewhere.

enter image description here

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    Linear is not necessarily invertible. – Kimball Jun 9 '16 at 9:07
  • @Kimball That is correct: linearity only implies invertibility iff there is a linear companion operation, ie: S ◦ T =I_U <==> T ◦ S = I_V. Thank you for pointing this out. – DevNull Jun 9 '16 at 15:43

From the mathematics perspective, such an operation can be considered bijective or capable of bijection.

As an example, encryption is bijective - for a given input, you can map it to a single encrypted result, which than then be perfectly undone back to the given input and ONLY the given input.

Contrast this with a one-way function, such as hashing - the operation cannot be undone.

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    While your reasoning sounds solid, I'm pretty certain that no lay person understand what this means without thorough explanation. Personally, I know about the word "bijection", but to me that's a specific kind of math function which has nothing to do with undoability of actions. – Mr Lister Jun 11 '16 at 13:03

Just for interest's sake, here's a couple of nice words that work for non technical situations when you can more or less do something without yet fully committing to it:

(In your technical sense I would agree that reversible works best.)


You could use transaction as in transactional operation or mutation as in mutable operation. A database transaction is capable of being reversed. Bank transactions can be reversed. Mutable means adj. Capable of or subject to change or alteration.; adj. Prone to frequent change; inconstant: mutable weather patterns.

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    A transaction is atomic, but it doesn't mean that it is undoable once it is committed. – 200_success Jun 9 '16 at 16:31

Agreed with reversible but as another option (from M-W):


capable of being readily changed

protected by user140086 Jun 9 '16 at 7:16

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