The term "on mend" is used to describe something or someone that is gradually recovering from an illness or a setback. Antonyms for this phrase could include "deteriorating," "worsening," "regressing," or "declining." If something is on the mend, it is moving in a positive direction, but if it is deteriorating, it is moving in the opposite direction. Instead of improving, a patient can regress and start to feel worse. Similarly, an economy can decline, causing more financial hardship rather than recovering from a recession. When we use antonyms to describe the opposite of "on the mend," we are highlighting the negative direction or lack of progress.