The most common and most likely answer to this crossword clue is the 10 letter word DECIMATION
I've seen this crossword clue in Independent
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More clues leading to the result DECIMATION
Buddy explains!
The straight part
We know that "Significant destruction" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case significant destruction = decimation.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 DECIMATION mean?
DECIMATION noun- (strictly) The killing or punishment of every tenth person, usually by lot.
- (generally) The killing or destruction of any large portion of a population.
- A tithe or the act of tithing.
- The creation of a new sequence comprising only every nth element of a source sequence.