More octennial refers to something that happens or occurs every eight years. Some synonyms that can be used in place of the term more octennial include "eight-yearly," "octennarian," "octennial," and "octal." These words can help to describe events or occurrences that happen once every eight years, such as an election or a certain celebration. Using synonyms like these can help to make a piece of writing more varied and interesting, as well as more precise. It can also help to avoid repetition and make the writing seem more polished and professional.