Weapon to pass over French island (7)
I believe the answer is:
missile
'weapon' is the definition.
(missile is a kind of weapon)
'pass over french island' is the wordplay.
'pass over' becomes 'miss' (both can mean to avoid touching**).
'french island' becomes 'ile' (French for 'island').
'miss'+'ile'='MISSILE'
'to' is the link.
(Other definitions for missile that I've seen before include "Cruise, perhaps" , "Projectile (sometimes guided)" , "One could get fired" , "weapon that's fired" , "Weapon that is propelled" .)