Onomatopoeia is the formation of a word that imitates or sounds like the source of the sound it describes. Therefore, finding synonyms for "more onomatopoetic" can be quite tricky. However, there are some words that could describe the same concept, such as "echoic," "mimetic," "phonetic," and "reverberating." These words denote the idea of a word or sound that echoes or imitates the sound it represents. Other potential alternatives to "more onomatopoetic" include "rhythmic," "mimicking," "mimic," and "imitative." Ultimately, the best synonym will depend on the context in which it is used and the specific sound that is being described.