Undergone, often used to describe a process or experience that one has undergone or passed through, has a few antonyms that indicate a lack of change, progression, or transformation. Some possible antonyms include "untouched," "unchanged," "unaffected," "unmodified," "unvaried," and "untransformed." These antonyms suggest that something has not experienced any alteration, development, or growth, and has remained in its original state. Similarly, words like "unexplored," "untrodden," and "unvisited" may also be considered antonyms of "undergone" as they imply a lack of travel, exploration, or experience. The choice of antonym depends on the context and the desired meaning, but each one provides a unique perspective and a distinct contrast to the idea of undergoing a process.