The antonyms for the word "more unfunctional" could be "functional," "efficient," "effective," "productive," "useful" and "practical." While "more unfunctional" suggests that something is ineffective or not working properly, the antonyms indicate that the object or system is functioning well, to the best of its capabilities. For instance, rather than using a "more unfunctional" old computer, it would be better to use a new and "efficient" computer that gets the job done optimally. Similarly, choosing a "functional" and "practical" car for daily use is more preferable than opting for an old, "unfunctional" vehicle that creates problems frequently. Antonyms help to accurately describe the quality of objects, systems or ideas.