The word "questionablenesses" refers to the state of being uncertain or doubtful in terms of authenticity or legality. Its antonyms are words that convey the opposite meaning or state. Some of the antonyms of "questionablenesses" are authenticity, legitimacy, acceptability, validity, and credibility. These antonyms suggest that something is unquestionable or beyond doubt, certain, and trustworthy. They are words that indicate a high level of reliability, truthfulness, or legality. Using these antonyms can help to strengthen a statement or argument by emphasizing the certainty and authenticity of the information provided. Overall, antonyms are essential tools for effective communication and expressing precise meaning.