The phrase "am unison" means to be in complete agreement or cooperation with someone else. Antonyms of "am unison" could be phrases such as "at odds," "disagreeing," or "out of sync." In these situations, individuals or groups are not able to work together harmoniously, potentially leading to conflict or misunderstandings. Antonyms could also include phrases such as "acting independently," "having differing opinions," or "not united." These phrases suggest that people or groups are not working together towards a common goal or purpose, leading to a lack of cohesion and potentially hindering progress.