The word "un-derivative" implies that something is not derived or copied from something else. Therefore, antonyms for this word would refer to things that are taken from other sources. Some examples of antonyms for "un-derivative" include derivative, unoriginal, imitative, uncreative, plagiarized, copied, and uninspired. These words describe works or ideas that are not original and lack creativity. While being un-derivative can be a positive attribute, being derivative or unoriginal could also have some value in certain contexts, such as learning new skills or imitating works to develop one's own style. Nevertheless, the antonyms for un-derivative highlight the importance of being original and creating something unique.