'apparitor' originates from Latin, specifically the word 'apparitōr' (apparitōr), where 'apparēre' meant 'to appear' or 'to be present' and the agent suffix '-tōr' indicated 'one who'.

'apparitōr' in Classical Latin (meaning 'one who is present, an attendant') passed into Medieval Latin as 'apparitor' with the specialized sense of an attendant who carried out official duties; English adopted the term (chiefly in legal and ecclesiastical contexts) from Medieval/Legal Latin in the late Middle Ages and Early Modern period.

Initially it meant 'one who is present' or 'attendant'; over time the sense specialized to 'an officer who serves writs or executes orders', especially in court and church contexts.