Possibly a drag for an Irish policeman (5)
I believe the answer is:
garda
'irish policeman' is the definition.
(I've seen this before)
'possibly a drag for an' is the wordplay.
'possibly' indicates anagramming the letters.
'for' means one lot of letters go next to another.
'an' becomes 'a'.
'drag' anagrammed gives 'gard'.
'gard'+'a'='GARDA'
(Other definitions for garda that I've seen before include "Irish state police force" , "Irish police officer" , "An Irish limb of the law" , "One of our police - what a drag" , "Cop" .)