The term "more unfantastic" refers to something that is even less impressive or exciting than it already is. The antonyms for this term would include words like "fantastic," "wonderful," "amazing," "exciting," and "sensational." These words all describe something that is impressive, exciting, and worth experiencing. Other antonyms could include words like "dull," "boring," "ordinary," "mediocre," and "unremarkable," all of which suggest that something is less than impressive and not worth getting too excited about. Overall, the antonyms for "more unfantastic" all describe things that are the complete opposite of what the original term suggests.