a supply of arms:Britain’s nuclear armoury expanded
US a place where arms are manufactured.
2an array of resources available for a particular purpose:his armoury of comic routines
3North American a place where militia units drill and train.
Middle English (in the sense 'armour'): from Old French armoirie, armoierie, from armoier 'to blazon', from arme 'weapon' (see arms). The change in the second syllable in the 17th century was due to association with armour
armoury in other Oxford dictionaries
Definition of armoury in the US English dictionary