Antonym of the verb "complete"

I have an action on a web form. It's a button whose action is to complete a case.

I need to name another button, and I want to use a verb that conveys the meaning of "undo the completion" of this case.

What's an appropriate antonym for the verb complete?

• uncomplete — is this a real verb?
• decomplete — is this a real verb?
• other?

Button 1 is "Complete Case".

Button 2 needs its opposite.

It depends on what you are trying to do, and the broader context:

• If you are simply stopping the process before completion Cancel would be appropriate
• If you have made a change but want to back out Undo would be appropriate
• If "Complete" is a record state, you have set a record to complete, and want to change that then "Make Incomplete", or "Back Out" would be appropriate.

In the last case it might also be possible to simply label the button "Incomplete", or have some sort of state combo to change the state, and then have a save button to commit.

However, there is no direct antonym to "complete".

FWIW, in user interface design it is often more appropriate to use a common idiom than it is to be strictly precise in the wording of your button.

There is no word for undoing completion of X specifically, so the next best plan would be to use the word "undo" or a synonym.

As far as I can see, you may have to go with:

[Complete Case] and [Undo Completion] or [Revoke Completion]

Button 2 would then be relying on the context provided by button 1.

I'm interpreting complete a case to mean declare this series of events complete. But that breaks the case metaphor. Cases don't complete, they open and close.

If you change your button to say close case, the inverse would be reopen.

The answer to what you want is:

cancel

or

save for later.

The first means 'don't complete this item, I don't want to complete it at all'. The second item means 'I don't want to complete this write now, but I don't want to lose my work'.

Since you don't mention or imply anything about saving work, I'd guess you really meant cancel.

For completeness, the answer to the title question is:

start.

That is, start is the only antonym of complete.