Aristocrat in a real mess (4)
I believe the answer is:
earl
'aristocrat' is the definition.
(I know that earl is a type of aristocrat)
'real mess' is the wordplay.
'mess' indicates anagramming the letters.
'real' with letters rearranged gives 'EARL'.
'in a' is the link.
(Other definitions for earl that I've seen before include "Aristocrat ranking between marquis and viscount" , "Count" , "British peer and Dublin street" , "Rank below marquess" , "Real (anag) - nobleman" .)