Unascertained is a word that describes something that is unknown or undetermined. The antonyms for unascertained are words that describe something that is known or certain. Some antonyms for unascertained include determined, certain, confirmed, established, identified, known, settled, and verified. They all imply that there is clarity or certainty surrounding a particular subject or situation. The use of antonyms for unascertained can help to provide clarity and direction when discussing topics where certainty is essential. Therefore, it is crucial to have a good understanding of these antonyms to ensure seamless communication in various contexts.