A female with a romantic and/or sexual interest in other females.
It is said that every female who roleplays is a lesbian, either closeted or open about it. The internet makes it easy for those too shy to be open IRL to flaunt themselves as one OOCly.
The above statement isn't necessarily always true, but there does seem to be high number of roleplayers who are very outspoken about their lesbian sexuality.
If a roleplayer is female, but not a lesbian, they are trans.