Cryptic crossword clue
Use of firearms spoiled plan fellow conceals 7

The most common and most likely answer to this crossword clue is the 7 letter word GUNPLAY

I've seen this crossword clue in The Sunday Telegraph
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Buddy explains!

The straight part
We know that "Use of firearms" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case use of firearms = gunplay.
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 GUNPLAY mean?

GUNPLAY noun
  1. The discharge of firearms, usually with violent intent and in confrontations.
  2. (BDSM) A sexual practice involving the use of a (usually unloaded) firearm for physical and mental stimulation.

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