The most common and most likely answer to this crossword clue is the 12 letter word CANCELLATION
I've seen this crossword clue in The Guardian
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Buddy explains!
The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CANCELLATION mean?
CANCELLATION noun- The act, process, or result of cancelling; as, the cancellation of certain words in a contract, or of the contract itself.
- The operation of striking out common factors, in both the dividend and divisor.
- A postmark that marks a postage stamp so as to prevent its reuse.
- In United States intellectual property law, a proceeding in which an interested party seeks to cancel the registration of a trademark or patent.
- The property of being cancellate.