The most common and most likely answer to this crossword clue is the 6 letter word WHOOSH
I've seen this crossword clue in The Guardian
W
H
O
O
S
H
More clues leading to the result WHOOSH
Buddy explains!
The straight part
We know that "passing wind by the sound of i/t" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case passing wind by the sound of i/t = whoosh.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 WHOOSH mean?
WHOOSH noun- A breathy sound like that of an object passing at high speed.
- To make a breathy sound like a whoosh.