The word "un-supportable" refers to something that cannot be justified or backed with sufficient evidence or reasoning. The antonyms for this term are "supportable," "defendable," "justifiable," and "reasonable." These words suggest a sense of validity, reliability, and soundness in a particular argument or claim. While "un-supportable" implies weakness, vagueness, or inconsistency, its antonyms highlight strength, clarity, and coherence. When choosing words to express an argument or viewpoint, it is important to use language that accurately and effectively conveys one's message. Using antonyms for "un-supportable" can not only strengthen one's position but also enhance the persuasiveness of their argument.