The word "rumbustious" is often used to describe someone or something that is boisterous, wild, or energetic. However, sometimes a situation calls for a more subdued, calm approach. In such cases, it may be useful to have appropriate antonyms for the word "most rumbustious." Some possible choices include words like peaceful, gentle, serene, placid, tranquil, and quiet. These words are useful when describing things like a calm lake, a peaceful meadow, or a quiet library. By using antonyms to balance out the meaning of "most rumbustious," we can effectively communicate a greater range of emotions and attitudes.