Japanese governor carrying orient's latest weapon (7)
I believe the answer is:
shotgun
'weapon' is the definition.
(shotgun is a kind of weapon)
'japanese governor carrying orient's latest' is the wordplay.
'japanese governor' becomes 'shogun' (a chief in feudal Japan).
'carrying' is an insertion indicator.
'latest' indicates one should take the final letters.
The final letter of 'orient' is 't'.
'shogun' placed around 't' is 'SHOTGUN'.
(Other definitions for shotgun that I've seen before include "Smooth-bore weapon" , "arm" , "Hunting firearm" , "No thugs (anag) - weapon" , "Noughts (anag) - type of wedding" .)