The word "unmelodious" is used to describe something that lacks a pleasant melody or harmony. There are many antonyms for this word that can be used to describe something that is musical, euphonious, or tuneful. Some great antonyms for unmelodious include melodious, harmonious, musical, rhythmic, tuneful, euphonious, pleasing, sweet, and lyrical. Using these words in place of unmelodious can help to add more positive and descriptive language to your writing or speech, making it more engaging and enjoyable for your audience. So, the next time you are looking for an antonym for unmelodious, consider using one of these words to add more depth and meaning to your language.