Nobleman from near Lewes (4)
I believe the answer is:
earl
'nobleman' is the definition.
(earl is a kind of nobleman)
'from near lewes' is the wordplay.
'from' indicates a hidden word.
'EARL' is hidden within 'near lewes'.
(Other definitions for earl that I've seen before include "Lear (anag)" , "Countess his wife" , "Aristocrat ranking between marquis and viscount" , "Sandwich perhaps" , "Rank immediately above viscount" .)