Pound returned by fair English fellow (5)
I believe the answer is:
bloke
'fellow' is the definition.
(I've seen this before)
'pound returned by fair english' is the wordplay.
'pound' becomes 'lb' (synonyms).
'returned' says the letters should be written in reverse.
'by' says to put letters next to each other.
'fair' becomes 'ok'.
'english' becomes 'E' (abbreviation).
'lb' in reverse letter order is 'bl'.
'bl'+'ok'+'e'='BLOKE'
(Other definitions for bloke that I've seen before include "Geezer" , "Chap, lad" , "Fellow (informal)" , "Chap, man" , "British fellow or chap" .)