Flexible is the quality that represents the ability to be bent or changed without breaking. On the other hand, its antonym is "non-flexible," which means a person or thing is rigid, inflexible, and incapable of adapting or adjusting to situations. Some antonyms for "non-flexible" are flexible, adaptable, supple, pliable, limber, loose, pliant, malleable, elastic, and mobile. A non-flexible person lacks an open-minded, innovative, and resilient approach to situations, while someone with a flexible mindset is open to change, receptive to alternative perspectives, and able to bounce back from setbacks. In summary, non-flexible is the opposite of flexibility, and a non-flexible approach can result in missed opportunities, lack of growth, and stagnation.