German has a French weapon (3)
I believe the answer is:
gun
'weapon' is the definition.
(gun is a kind of weapon)
'german has a french' is the wordplay.
'german' becomes 'g' (abbreviation).
'has' says to put letters next to each other.
'a french' becomes 'un' ('a' in French).
'g'+'un'='GUN'
(Other definitions for gun that I've seen before include "What has barrel" , "Firearm" , "Hand weapon" , "Throttle" , "Hired killer" .)