Nobleman in real distress (4)
I believe the answer is:
earl
'nobleman' is the definition.
(member of the nobility)
'real distress' is the wordplay.
'distress' indicates an anagram.
'real' is an anagram of 'EARL'.
'in' acts as a link.
(Other definitions for earl that I've seen before include "A real sort of lord" , "Jimmy Carter's middle name" , "-- Grey, PM 1830-34" , "Male equivalent of a countess" , "Count" .)