I had an ah ha moment on Friday morning that made me think maybe I'm not TG and I can be 'stable' as gender fluid. I looked in mirror (hadn't shaved in two days) and realized I looked like a guy, like full on and something clicked, I'm gender fluid and loving it!

As for a definition, for me at least it's being comfortable with face fur OR foundation depending on my mood, and feeling like I fit in with a bunch of 'ranging bulls' just as easily as with a bunch of women.