'responsorial' originates from Medieval/ Late Latin, specifically from the noun 'responsorium', where the verb 'respondere' meant 'to answer'.

'responsorial' developed from Medieval Latin 'responsorium' → Old French/Anglo-Norman forms (e.g. 'responsorie'/'responsory') → Middle English 'responsory', with the adjective formed by adding the suffix '-al' to create the modern English 'responsorial'.

Initially it meant 'pertaining to an answer or response'; over time it came to be used specifically for liturgical or musical practices involving alternating call-and-response (a 'responsory').