Crossword Genius

Whistling in the galley is releasing the tension (7,3,5)

Ross

I believe the answer is:

letting off steam

I'm a little stuck... Click here to teach me more about this clue!

'the galley is releasing the tension' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'whistling in' is the wordplay.
I cannot quite see how this works, but
'in' is within the answer.
This explanation may well be incorrect...

Can you help me to learn more?

I've seen this clue in the Irish Times.
Want a hint initially instead of a full solution? Install my app