Weapons store (7)
'weapons store' is the definition.
(store for weapons or ammunition)
This is all the clue.
(Other definitions for arsenal that I've seen before include "London premiership football team" , "A military store of guns and armaments" , "Premier League side founded by munitions workers in 1886" , "Store of weaponry" , "Ammunition store or English soccer team" .)
'weapons store' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for armoury that I've seen before include "Means" , "Arsenal - magazine" , "Collection of weapons" , "Weapons store" , "Weapon store" .)