The most common and most likely answer to this crossword clue is the 2 plus 3 plus 2 letter word AT ONE GO
A
T
O
N
E
G
O
More clues leading to the result AT ONE GO
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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.