The most common and most likely answer to this crossword clue is the 6 letter word UNSTOP
I've seen this crossword clue in The Daily Telegraph
U
N
S
T
O
P
More clues leading to the result UNSTOP
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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 UNSTOP mean?
UNSTOP verb- To remove a stoppage; to clear a blockage.
- To unplug or uncork a container.
- To draw out the stops of (an organ).