The antonyms of "unfinished" include "completed," "finished," "done," "concluded," "terminated," "settled," "perfected," "accomplished," "polished," and "ended." Each of these words carries a different connotation but all indicate that something has been brought to a satisfactory completion. While unfinished refers to something that remains incomplete or not yet done, the antonyms suggest that the task has been seen through to the end. Using these antonyms in place of unfinished can help to convey a sense of achievement and finality, emphasizing the successful completion of a task or project.