_WT is a term used to describe the female counterpart of a male. The _ is reserved for a males name. WT stands for, with tits.
Person 1: Wow! Bob and his sister look a lot alike.
Person 2: No shit bro...she's BWT (example of _WT).
Person 1: Huh?
Person 2: Bob with tits.
Person 1: Hahaha.