Someone who gets so drunk (usually at a dive bar) that it is apparent to everyone that they should call a professional to get them home.
Typically these are 40-60 year old men that wear depends and occasionally fall asleep mid sentence.
Bar Patron #1: This old fucker at South River Bar was so wasted he fell asleep while hitting on some fat road whore.
Bar Patron #2: Shit that asshole is Taxi Cab Drunk, hope he has his diapers on!