Irresilient, meaning lacking in resilience, can have several antonyms, including resilient, durable, elastic, strong, flexible, and pliable. Resilient refers to the ability to recover quickly from difficulties and setbacks. Durable is the opposite of something that easily breaks, lasting longer than expected or able to withstand wear and tear. Elastic refers to something that can stretch and then return to its original shape. Strong describes an object that can withstand pressure or force without breaking. Flexible is the characteristic of something that can bend or change easily without breaking. Finally, pliable suggests an object that can be easily molded or reshaped without breaking.