The term "clip-on" refers to an object that can be attached or fastened onto something else. Its antonyms are "permanent" and "detachable." Permanent signifies that something is meant to be fixed and cannot be removed or separated. On the other hand, detachable pertains to an object that can be easily taken off without causing any damage. Other antonyms for clip-on can include built-in, integrated, and fixed. These words often describe objects that are not meant to be removed or changed, unlike clip-ons, which can be easily replaced or interchanged.