Being on par is a common phrase used to describe two things that are equal or balanced. However, there are several antonyms that can be used to describe a situation where things are not on par. These antonyms include unequal, imbalance, disparity, and incongruity. Unequal suggests a lack of balance or fairness between things, while imbalance implies a state of disorder or instability. Disparity refers to a significant difference or inequality between two things, while incongruity suggests a lack of harmony or agreement between them. When things are not on par, it may be necessary to address the root cause of the problem and work towards achieving a more balanced and equitable outcome.