Subordinate settles in courtroom clothes (10)

I believe the answer is:

undervests

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

'subordinate settles' is the definition.
I know nothing about this answer so I can't tell whether this works.

'courtroom clothes' is the wordplay.
'courtroom' becomes 'under' (I can't explain this - if you can you should give a lot more credence to this answer).
'clothes' becomes 'vests' (vesting is a kind of clothing).
'under'+'vests'='UNDERVESTS'

'in' is the link.

Can you help me to learn more?

I've seen this clue in The 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.