Court until bra is undone (8)
I believe the answer is:
tribunal
'court' is the definition.
(I know that court can be written as tribunal)
'until bra is undone' is the wordplay.
'is undone' indicates an anagram.
'until'+'bra'='untilbra'
'untilbra' anagrammed gives 'TRIBUNAL'.
(Other definitions for tribunal that I've seen before include "Adjudication body" , "Court appointed to look into a particular matter" , "case" , "Court, investigative board" , "Official board" .)