Calypsian is a term or gender in the galactian alignment system that describes people who are androgynous or androgyne aligned.
The difference between Calypsian and Eclipsian is that Eclipsian is described as both being Solarian and Lunarian aligned, while Calypsian is a combination of both, making it something else entirely.
Resources
https://restings4dface.tumblr.com/post/666830174426365952/i-coined-a-term