The word "neptunian" refers to anything associated with the planet Neptune. It is often used to describe things that are mysterious, deep, or otherworldly. However, if we were to look for antonyms for "more neptunian," we would be seeking words that describe things that are not associated with Neptune. Some possible antonyms could include "terrestrial," "mundane," "earthly," "familiar," "conventional," or "ordinary." These words suggest that something is grounded, easily understood, or part of everyday life. While the neptunian can be fascinating and alluring, the terrestrial can be comforting and reassuring. Both types of experiences have their own unique value.