The phrase "most unvaried" implies a lack of diversity or monotony. Some antonyms to describe something that is varied or diverse could include colorful, multifaceted, eclectic, diverse, or versatile. Something that is constantly changing and cannot be easily defined as having one set identity or attribute could be described as mercurial or unpredictable. When discussing something that is the opposite of unvaried, it often helps to consider the specific context in which the term is being used. For example, a person's life might be described as "most unvaried" if they follow a strict routine every day, while a vibrant city full of diverse cultures and experiences might be the antithesis of such a description.