The word "un-grounded" is commonly associated with ideas, beliefs, or actions that lack a solid foundation or rationale. To find antonyms for this word, we would look for terms that suggest stability, reliability, or authenticity. Some possible antonyms could include words like grounded, anchored, rooted, established, justified, substantiated, or supported. These terms imply that there is a valid reason or evidence for a certain idea, and that it is not simply based on conjecture or hearsay. By seeking out antonyms for "un-grounded," we can deepen our understanding of what it means to have a well-supported argument or belief system.