The word "more unascertained" suggests a level of uncertainty or vagueness about something. Therefore, its antonym would be words that indicate clarity or certainty. Some antonyms for "more unascertained" could include "confirmed," "certain," "determined," "established," "verified," "definite," "exact," "precise," "specific," "evident," and "clear." These words suggest a high degree of accuracy or certainty about a particular thing or situation. Antonyms for "more unascertained" are important as they help communicate a sense of clarity and precision in speech and writing. Choosing the right words can help to convey information more effectively and reduce ambiguity.