The antonyms for the word "more ascertained" could include words like uncertain, unknown, ambiguous, unclear, indefinite, tentative, or doubtful. When something is not fully ascertained, there is a lack of confidence or surety in its validity or accuracy. Uncertainty implies a lack of knowledge or information, while ambiguity suggests a situation that is open to different interpretations. Indefinite and tentative suggest that there is still much to be determined, and doubtful implies a strong lack of belief or trust. These words provide opposing meanings to "more ascertained" and indicate that there is still much to be discovered or confirmed.