The antonyms for the word "un-bent" refer to various states of being bent or curved. These include words such as bent, curved, twisted, warped, and contorted. These antonyms are commonly used to describe objects or surfaces that have been subjected to some form of physical manipulation, such as metal bars, cables, or sheets of paper. They can also be used to describe the physical posture of human beings or animals, as well as their facial expressions. Depending on the context, the antonym of "un-bent" may also be straightened, flattened, smoothed, or fixed.