The antonym for 'more irrefrangible' could be 'less convincing'. Irrefrangible means impossible to refute or break, so the opposite of that would be something that is easily challenged or broken. Other antonyms for irrefrangible could include precarious, fragile, breakable, or flimsy. These words describe things that can be easily damaged or destroyed, unlike something that is irrefrangible. By understanding antonyms, we can better appreciate the complexity of language and use different terms to increase the impact of our communication. When we can find suitable antonyms, we can better convey the exact meaning we want to express.