Envy B_, for example Barnaby? (8)
I believe the answer is:
begrudge
'envy' is the definition.
(I know that envy can be written as begrudge)
'b for example barnaby?' is the wordplay.
'for example' becomes 'e.g.' (short for 'exempli gratia', 'for example' in Latin).
'barnaby?' becomes 'rudge' (Barnaby Rudge is a Dickens novel).
'b'+'eg'+'rudge'='BEGRUDGE'
(Other definitions for begrudge that I've seen before include "Envy another's possessions or good fortune" , "Resent other's good fortune or possession" , "Envy the pleasure of" , "Show envy" , "Envy, resent having to give" .)