"Set at ease" means to comfort someone and make them feel relaxed or relieved. There are several synonyms for this phrase depending on the context in which it is used. Some of these synonyms include "calm," "relax," "soothe," "pacify," "reassure," "appease," "ease," and "comfort." All of these words represent the act of providing emotional support and helping someone to feel less anxious or stressed. Depending on the situation, the most appropriate synonym for "set at ease" may differ. However, they all achieve a similar goal in helping someone feel more calm and content.