Courts Romeo in a Butlin’s resort (9)
I believe the answer is:
tribunals
'courts' is the definition.
(I know this)
'romeo in a butlin's resort' is the wordplay.
'romeo' becomes 'r' (phonetic alphabet: alpha, bravo, charlie etc.).
'in' means one lot of letters goes inside another.
'resort' indicates anagramming the letters (re-sort the letters).
'a'+'butlins'='abutlins'
'abutlins' with letters rearranged gives 'tibunals'.
'r' put within 'tibunals' is 'TRIBUNALS'.
(Other definitions for tribunals that I've seen before include "Boards settling disputes" , "Investigating courts" , "insult - bar involved" , "Boards of officials appointed to enquire into matters - we've got our share" .)