There are many synonyms for the phrase "sagging in folds." Some of the most common ones include drooping, hanging, swagging, slumping, sagging, and flabby. Other synonyms include slack, limp, loose, flaccid, and wavering. No matter which synonym you choose, the overall idea is the same: there is some type of downward movement or lack of tension in the object or substance. Whether you're talking about a piece of clothing that's become too worn or a part of the human body that's starting to lose its elasticity, there are many different ways to describe something that's sagging in folds.