bat gu
A traditional Chinese mainland whore who travels south to Taipei to solicit money in exchange for sexual favors from wealthy Taiwanese businessmen. Bat gu-s are also known as someone who has had extensive experience and therefore should be avoided at all times. Women who have less experience are known as "Gai." Bat gu also have a reputation for having "chou dao fu."
Chou went to Taiwan as a "bat gu" to find work outside of the mainland where everyone already knows her notorious reputation and has been spurned by her elders (jo-seen).