'armamentaria' originates from Latin, specifically the word 'armamentarium', where 'arma' meant 'arms' or 'tools' and the suffix '-mentum' indicated an instrument or means.

'armamentarium' was used in Medieval and Late Latin to mean a place or collection of equipment; it entered English usage (often in the singular 'armamentarium') and its plural form 'armamentaria' follows classical Latin pluralization.

Initially associated more narrowly with military arms or a store of weapons ('equipment'), its usage broadened to mean any collection of instruments or resources for a particular professional or technical purpose (especially medical instruments).