Undeniable is often used to describe things that are inarguable, irrefutable, and unquestionable. However, there are several antonyms for undeniable, which denote the opposite of the word. These antonyms include disputable, questionable, controversial, doubtable, and refutable. Disputable means that something is open to be argued, discussed or debated. Questionable implies that there is doubt or uncertainty over the validity or morality of something. Controversial means a topic that is likely to provoke disagreement or argument. Doubtable implies that something is questionable or may be disbelieved. Lastly, refutable means that the claim or evidence can be proven wrong or false. These antonyms provide a range of options for describing ideas or facts that are not certain or are open to interpretation.