The word "un-filled" can have several antonyms depending on its context. In terms of physical objects, the opposite of "un-filled" would be "filled", meaning that the object is complete or complete. If referring to emotions or moods, possible antonyms may include "satisfied", "content", or "fulfilled". Another possible antonym may be "crowded", as this implies that a space is full to capacity, whereas "un-filled" suggests otherwise. Alternatively, "overstuffed" or "cluttered" could also be antonyms for "un-filled" depending on the context. Ultimately, the antonym for "un-filled" depends on the specific situation it is used in.