In China, a revolutionary weapon (7)
I believe the answer is:
machete
'weapon' is the definition.
(machete is a kind of weapon)
'in china a revolutionary' is the wordplay.
'in' means one lot of letters goes inside another.
'china' becomes 'mate' ('China plate' is rhyming slang for 'mate').
'a revolutionary' becomes 'che' (Che Guevara the Marxist revolutionary).
'mate' enclosing 'che' is 'MACHETE'.
(Other definitions for machete that I've seen before include "Knife for hacking" , "Cheat me over broad heavy knife used in jungle" , "Jungle chopper" , "hacker" , "Jungle blade" .)