'antiphonally' originates from Greek, specifically the word 'antiphōnos' (ἀντίφωνος), where 'anti-' meant 'opposite' or 'in return' and 'phōnē' meant 'voice' or 'sound'.

'antiphōnos' passed into Late Latin as 'antiphona' (meaning a responsive chant), then into Middle English as 'antiphon' and the adjective 'antiphonal'; the adverb 'antiphonally' developed from the adjective with the addition of the suffix '-ly' to form the modern English word 'antiphonally'.

Initially, the root referred to 'a sound made in answer' or a 'responsive chant'; over time it evolved into the specific musical/performative sense 'by alternating or responsive singing', which is reflected in the modern adverb 'antiphonally'.