Time to manage revolutionary concerning weapon (9)
I believe the answer is:
truncheon
'weapon' is the definition.
(truncheon is a type of weapon)
'time to manage revolutionary concerning' is the wordplay.
'time' becomes 't' (abbreviation).
'to manage' becomes 'run' (both can mean to organise).
'revolutionary' becomes 'Che' (Che Guevara the Marxist revolutionary).
'concerning' becomes 'on' (both can mean 'in relation to').
't'+'run'+'che'+'on'='TRUNCHEON'
(Other definitions for truncheon that I've seen before include "Police staff" , "Cosh" , "Policeman's traditional weapon" , "Peelers' baton" , "Police baton" .)