Crossword Genius

Cabin not used by Captain Hook (10)

Ross

I believe the answer is:

roundhouse

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

'hook' is the definition.
(I know that roundhouse is a type of hook)

'cabin not used by captain' is the wordplay.
I cannot quite understand how this works, but
'not' could be 'un' (I've seen this in other clues) and 'un' is located in the answer.
This explanation may well be incorrect...

Can you help me to learn more?

(Another definition for roundhouse that I've seen is " place with a turntable".)

I've seen this clue in The Sunday Times.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.