Real sort of aristocrat (4)
I believe the answer is:
earl
'aristocrat' is the definition.
(I know that earl is a type of Lady)
'real sort' is the wordplay.
'sort' indicates an anagram.
'real' with letters rearranged gives 'EARL'.
'of' acts as a link.
(Other definitions for earl that I've seen before include "Real (anag) - nobleman" , "A real peer" , "British noble" , "A real titled lord" , "Male member of British nobility" .)