The word questionability means the state or quality of being doubtful, uncertain or ambiguous. Its antonyms are words that represent the opposite of this meaning. Some of the antonyms for the word questionability are certainty, clarity, conclusiveness, decisiveness, and unambiguity. When we say something is certain, we mean that it is not in doubt or questionable. Similarly, clarity implies that a statement or idea is easy to understand and cannot be misinterpreted. Conclusiveness means that an argument or reasoning has come to a definitive conclusion. Decisiveness refers to a resolute, firm, and clear-cut decision or judgment. Lastly, unambiguity suggests that a statement is free from any confusion or doubt.