Criminal once hurt with butt of iron club (9)
I believe the answer is:
truncheon
'club' is the definition.
(truncheon is a kind of club)
'criminal once hurt with butt of iron' is the wordplay.
'criminal' indicates anagramming the letters.
'with' is a charade indicator (letters next to each other).
'butt of iron' becomes 'n' (I can't justify this - if you can you should give a lot more credence to this answer).
'once'+'hurt'='oncehurt'
'oncehurt' anagrammed gives 'truncheo'.
'truncheo'+'n'='TRUNCHEON'
Can you help me to learn more?
(Other definitions for truncheon that I've seen before include "Cosh" , "Police staff" , "Policeman's club" , "Police baton" , "Policeman's traditional weapon" .)