The phrase "most la-dee-da" implies a haughty or pretentious attitude. Antonyms for this phrase could include down-to-earth, unpretentious, humble, modest, or straightforward. Using more descriptive language, one could describe a person who is the opposite of "most la-dee-da" as genuine, sincere, authentic, or even plain-spoken. Those who are not "most la-dee-da" may also be described as approachable, easy-going, or unassuming. Overall, these antonyms for "most la-dee-da" suggest a more relatable, approachable person who is not concerned with showing off or trying to impress others.