A contraction of the phrase "transsexual lesbian". A transbian is a male-to-female transsexual who is also a lesbian - ie. a transsexual woman who is sexually attracted to other women.
"Probably more than half the trans women I know are transbians or bi. Fewer than half are straight."
Straight/bi men with a lesbian fetish so intense that they started calling themselves lesbians. Frequently complains about cis lesbians not wanting their “organicstrap”, aka male genitalia.
transbian: this cis lesbian at a lesbian bar turned me down!
A transsexual woman (born male and transitions completely to female) who is a lesbian and is also willing to date other tgirls.
Example 1: "No one can love you like one of your sisters" - a transbian
Example 2:
Guy #1: Dude, look at those chicks. They're frenching right in front of us!
Guy #2: Dude!
Guy #1: Wait... dude, I think they're dudes!
Girl: We're transbians. Get it right!
Guy #1: Woah... hawt.