The most common and most likely answer to this crossword clue is the 8 letter word BLOWPIPE
I've seen this crossword clue in The Daily Telegraph
B
L
O
W
P
I
P
E
More clues leading to the result BLOWPIPE
- Small missile launcher ineffective in the end after setback, just defeat
- Weapon giving minimal offence in Belgium and Spain
- Possible means of spreading poison or spleen, through phone mostly
- Disaster to decorate cake as poisoner?
- Setback star encountered at first, finding plumber’s tool
- Weapon whose user shows a lot of cheek
Buddy explains!

The straight part
We know that "Weapon whose user shows a lot of cheek" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case weapon whose user shows a lot of cheek = blowpipe.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 BLOWPIPE mean?
BLOWPIPE noun- A narrow tube through which a jet of air is directed onto a flame; used in the analysis of minerals etc and in jewelry manufacture
- A weapon through which darts may be shot by blowing; a blowgun
- A long narrow pipe, rotated in the hands, upon which glassware is blown