The antonyms for the word "un-used" include "used", "applied", "utilized", "employed", "active" and "operated". All these words are opposite in meaning to "un-used" which implies that something has not been used, applied or employed. For instance, the term "used" means something that has been utilized or applied. Similarly, "utilized" refers to something that has been put to use or employed for a specific purpose. On the other hand, "active" and "operated" suggest that something is in use or working. These antonyms are important to understand the context of a sentence and capture the author's intended meaning accurately.