Peer in real trouble (4)
I believe the answer is:
earl
'peer' is the definition.
(earl is a kind of peer)
'real trouble' is the wordplay.
'trouble' indicates an anagram.
'real' with letters rearranged gives 'EARL'.
'in' acts as a link.
(Other definitions for earl that I've seen before include "... Grey, fragrant Oriental tea" , "Rank below marquess" , "Aristocrat ranking between marquis and viscount" , "-- Grey, PM 1830-34" , "A lord like Lear" .)