The term "principal meals" is used to refer to the main meals of the day, which usually include breakfast, lunch, and dinner. There are many synonyms for this term, such as "main meals," "major meals," "core meals," or "primary meals." Other terms that may be used include "substantial meals," "important meals," or "essential meals." Additionally, some people may refer to these meals as "daily meals," "necessary meals," or simply "meals." Regardless of the specific term used, the principal meals of the day are crucial for maintaining overall health and wellbeing by providing the body with necessary nutrients and energy.