The term "most irrefragable" refers to something that is impossible to dispute or deny. However, in contrast, there are various antonyms that describe the opposite, including disputable, refutable, voidable, and questionable. These words imply that the claim or statement can be challenged or contradicted, making it uncertain and subject to debate. In contrast to "most irrefragable," these antonyms suggest that there may be valid reasons to question the validity of the statement or claim. Therefore, it is essential to consider these antonyms when evaluating different arguments and making informed choices based on the available evidence.