The phrase "get worse" describes a negative change or deterioration in a situation or condition. However, there are many synonyms one could use to express this idea. Some examples include "deteriorate," "decline," "degenerate," "worsen," "fall apart," "go downhill," and "take a turn for the worse." Each of these words conveys the idea of things getting worse, but they may be more appropriate depending on the context. For instance, "deteriorate" or "degrade" may be used when referring to a physical object or infrastructure, while the phrase "take a turn for the worse" may be used when referring to a person's health or a situation that was once hopeful but suddenly becomes negative.