Noble paragon deprived of power (4)
I believe the answer is:
earl
'noble' is the definition.
(earl is a kind of noble)
'paragon deprived of power' is the wordplay.
'paragon' becomes 'pearl' (I've seen this before).
'deprived of' indicates named letters should be taken away.
'power' becomes 'p' (symbol in physics).
'pearl' with 'p' taken out is 'EARL'.
(Other definitions for earl that I've seen before include "British peer and Dublin street" , "Husband of a countess" , "British noble" , "Essex, say" , "A real sort of lord" .)