The term "most vowel" refers to a word that contains the highest number of vowels. However, there are several synonyms that can be used in place of this term. For instance, you can use the phrase "most vowel-rich word," which means the same thing but is more descriptive. You can also use "most vowel-laden word," which gives the impression that the word is filled to the brim with vowels. Another synonym is "most vowel-heavy word," which emphasizes the weight or significance of the vowels in the word. Overall, using synonyms can help you vary your vocabulary and make your writing more interesting to read.