The word "most refutable" means that something is easily disputed or proven false. The antonym for this phrase would be "irrefutable," which means that something is impossible to refute or disprove. Thus, if something is irrefutable, it is beyond doubt or question. Other antonyms for "most refutable" could include "undeniable," "indisputable," "certain," or "incontrovertible." These words signify that something is true or right, and cannot be argued against. Therefore, when searching for the opposite of "most refutable," it is important to consider words that convey certainty and absolute truth.