Synonyms for the phrase "prime of the morning" can refer to the best time of the day. Some alternatives could be "dawn," "sunrise," "early morning," or "daybreak." These words evoke a sense of freshness and newness, as if everything is just beginning. Another set of synonyms could focus on the idea of energy and vitality. Words like "vigorous," "lively," "dynamic," and "energetic" all suggest a feeling of being awake and ready to take on the day. The prime of the morning is a special time when anything seems possible, and these synonyms help to capture that feeling.