The phrase "keeps at bay" is often used to describe the act of preventing something undesirable from happening or keeping a problem under control. There are many synonyms that can be used to express this idea, including "stave off," "ward off," "deter," "hinder," "repel," "thwart," "forestall," "preempt," and "avert." Each of these words conveys the idea of actively working to prevent something from happening, whether through physical or mental means. By using these synonyms, writers can add variety and depth to their descriptions of how a person or group is dealing with a potential threat or challenge.