Chauffeur ostracised for pocketing coins (5)
I believe the answer is:
euros
'coins' is the definition.
(coins used in the Eurozone)
'chauffeur ostracised for pocketing' is the wordplay.
'pocketing' indicates the answer is hidden within the clue (I've seen 'pockets' mean this (pocket can mean to contain)).
'EUROS' is hidden in the letters of 'chauffeur ostracised for'.
(Other definitions for euros that I've seen before include "EU currency" , "Rouse (anag.)" , "Monetary units" , "Common currency" , "currency in Greece" .)