Antiphonic is a term used to describe a style of music or chant that utilises the alternation or opposition of voices or instruments. While there may not be direct synonyms to antiphonic, there are a few terms that are closely related to the concept. One of these is "call-and-response," which refers to a pattern of singing or playing where one voice or instrument issues a phrase that is then repeated or answered by another. Another similar term is "antithesis," which refers to a contrast or opposition of ideas or characteristics. Finally, "counterpoint" is another term that refers to the combination of multiple melodies or voices for a rich, complex sound.