The antonyms for the phrase "get together on" are unsynchronized, uncoordinated, disperse, and separated. When people don't agree on something or lack consensus on an idea or plan, they tend to be disperse or uncoordinated. Individuals may have different opinions, goals, or interests, making it challenging to get together in a cohesive manner. Even when people do agree, sometimes circumstances make it impossible to get together. Our daily lives are so fast-paced, and we are often pulled in multiple directions that we lack synchronization with others. Therefore, it is important to have effective communication and respect for diverse perspectives to achieve a common goal.