Caribbean bishop joining union leader in jail (5)
I believe the answer is:
cuban
'caribbean' is the definition.
(I've seen this before)
'bishop joining union leader in jail' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'joining' is a charade indicator (letters next to each other).
'leader' says to take the initial letters.
'in' indicates putting letters inside.
'jail' becomes 'can' (the can is American slang for prison).
The first letter of 'union' is 'u'.
'b' put after 'u' is 'ub'.
'ub' inserted into 'can' is 'CUBAN'.
(Other definitions for cuban that I've seen before include "islander" , "Citizen of Castro's country" , "Nationality of citizen of Havana" , "Relating to Castro's isle" , "Republican" .)