'vibratory' ultimately originates from Latin, specifically the verb 'vibrare,' where 'vibrare' meant 'to shake' or 'to move quickly to and fro.'

'vibrare' led to Late Latin forms such as 'vibratio' (a shaking) and adjectival Latin/Medieval Latin forms like 'vibratorius'; from these came the English verb 'vibrate' (via Middle/Modern Latin and French influence) and the adjective 'vibratory' formed in English with the suffix '-ory.'

Initially it was tied directly to the action 'to shake' (Latin); over time the sense shifted to adjectival uses meaning 'relating to or producing vibration,' which is the modern usage of 'vibratory.'