The word "breviloquent" means expressing oneself concisely or in few words. Therefore, the antonym of "most breviloquent" would be "most verbose," which means expressing oneself in a lengthy or wordy manner. Other possible antonyms include "most long-winded," "most prolix," "most loquacious," "most garrulous," and "most talkative." When communicating, it is essential to strike a balance between being too brief and too verbose. Being too brief may lead to miscommunication, while being too wordy may bore the listener or make it difficult for them to grasp your point. Therefore, it is best to communicate clearly, accurately, and succinctly.