The word "whippier" is often used to describe things or people that are thin, fragile, or delicate. Its opposite, however, would be words that describe something that is robust, strong, and sturdy. Some of the antonyms for whippier could be bulky, hefty, muscular, stocky, strong, thick, and stout. Another set of antonyms could be words that denote agility, flexibility, and nimbleness, such as athletic, graceful, limber, lithe, and supple. These antonyms offer a contrast to the fragility and delicateness that "whippier" implies, and help to expand the range of meanings that can be conveyed through the use of language.