The antonyms for the term "most hundred proof" could vary depending on the context in which the phrase is used. If it refers to an alcoholic beverage, some possible antonyms could be "non-alcoholic," "low-proof," or "weak." However, if the phrase is used to convey strength or certainty, some antonyms could be "doubtful," "uncertain," or "insecure." In terms of moderation or restraint, antonyms could include "excessive," "overindulgent," or "reckless." Ultimately, the antonyms for "most hundred proof" would depend on the subject matter and the desired opposite meaning.