The term "all sewn up" refers to something that is fully completed or has been settled. Its antonyms could be phrases like "still up in the air," "partially done," or "unfinished business." The opposite of "all sewn up" is something that is uncertain or unresolved. It could refer to a work in progress or a project with loose ends. The phrase may also mean that there is still room for improvement or change. This could be applied to various aspects of life, such as relationships, careers, or personal growth. All in all, the antonyms for "all sewn up" signify something that is not yet perfect and requires further attention.