The word "chuffier" is not commonly used in the English language, and therefore, it does not have a vast array of antonyms associated with it. However, one can infer the opposite of "chuffier" to be "less chuffy," or even "unimpressive" or "uneventful." Other possible antonyms for "chuffier" could include terms such as "calm," "serene," and "quiet." It is essential to note that antonyms are not always straightforward or exact opposites, and context plays a significant role in determining the most appropriate antonym to use for a given situation.