Fan Casting Ambiguous Gender in Sort by Tropes

Halfway between Lady Looks Like a Dude and Dude Looks Like a Lady is a character who in some way defies the conventions of male and female, and no-one can decide which side, if any, the character actually belongs on. Lots of subterfuge always follows, as everyone follows them around to try and determine their gender once and for all. Expect a Gender-Blender Name, lots of Gender-Neutral Writing and Pronoun Trouble. Usually, their gender will never be revealed, and no-one will be any the wiser, usually subject to The Un-Reveal. The technical term for this kind of person is "androgyne", from the Greek for "man-woman." Used as an adjective, it's "androgynous".