Nonbrittle means not easily breakable or cracking. Some antonyms for nonbrittle include brittle, fragile, delicate, frangible, and breakable. These words denote the opposite of nonbrittle, meaning they are easily breakable or prone to crack. However, some other antonyms for nonbrittle could include strong, tough, durable, sturdy, and resilient. These words imply that the object or material is not easily breakable and can withstand wear and tear. Nonbrittle is a desirable trait, especially for materials and objects that are subjected to pressure, tension, or impact. Choosing the appropriate antonym depends on the context in which the word is used.