Bureau right for a policeman (7)
I believe the answer is:
officer
'for a policeman' is the definition.
(synonyms)
'bureau right' is the wordplay.
'bureau' becomes 'office' (synonyms).
'right' becomes 'r' (common abbreviation).
'office'+'r'='OFFICER'
(Other definitions for officer that I've seen before include "Public servant" , "Holder of a commission in the armed forces" , "Serviceman (or woman) of rank" , "Policeman (or other authority)" , "Police constable" .)