The phrase "most zenithal" refers to something that is at the highest point or directly overhead. There are many synonyms for this term, such as apex, summit, acme, peak, pinnacle, top, climax, zenith, crown, and height. These words all convey the idea of something being at the highest point or pinnacle, whether it is a physical object or an abstract concept. Using synonyms for "most zenithal" can help to add variety and interest to your writing or speech, making it more engaging for your audience. So when looking to describe something that is at its highest point, try using one of these synonyms instead of the same old phrase.