Replanned is a verb that means to plan again. Therefore, the opposite or antonyms for replanned is to not plan or unplanned. Other antonyms for replanned include impromptu, spontaneous, and unprepared. These words suggest a lack of premeditation, foresight, or planning. Additionally, synonyms for unplanned or impromptu could be random, haphazard, accidental, or coincidental. Depending on the context, antonyms for replanned could vary; however, generally, it signifies a lack of organization, structure, or method. While some people may view spontaneity as a positive attribute, it can also lead to chaos and unpredictability.