Most vagarious is a term that describes something that is unpredictable, excitable, or erratic. Its antonyms would be words that describe something that is steady, consistent, or predictable. Some appropriate antonyms for most vagarious would include words like stable, calm, reliable, and dependable. These words suggest a sense of consistency and trustworthiness, qualities which are the opposite of what most vagarious implies. When looking for the opposite of most vagarious, it is essential to think beyond just literal antonyms and consider words that embody the opposite meanings of the word.