Basket-case generally refers to someone or something that is in a state of chaos or disarray. The antonyms to this word could be individuals or objects that are functioning and performing efficiently. Words like rational, coherent, sophisticated, and well-adjusted could be considered antonyms of basket-case. These terms refer to something that is competent and has the ability to hold together with a stable and organized approach. An individual or an organization that is well-organized, confident, and composed may fit the description of the antonyms for basket-case. Therefore, antonyms to this term may indicate order, stability, and resilience.