Here, in Scotland, you have to have some trousers on (5)
I believe the answer is:
troon
'here in scotland you have' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'have some trousers on' is the wordplay.
'have' becomes 'roon' (I can't explain this - if you can you should give a lot more credence to this answer).
'some' says to take the initial letters.
'on' says to put letters next to each other.
The first letter of 'trousers' is 't'.
'roon' after 't' is 'TROON'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for troon that I've seen before include "Open home" , "West Scottish town with links" , "Coastal town of West Scotland" , "Clyde port" , "Ayrshire golf course" .)