The term "jerry-built" refers to something that is poorly constructed or made with inferior materials. Antonyms for this word would include well-built, sturdy, durable, and sound. These words describe something that is built to last and can withstand the test of time. A well-built structure is one that has been constructed with care and attention to detail, using high-quality materials and skilled labor. A sturdy object is one that is strong and reliable, able to withstand wear and tear without breaking down. A durable item is one that is made to last, able to resist damage even under adverse conditions. Finally, a sound object is one that is solid and secure, free from defects and able to perform its intended function without fail.