What is Pocket Waitress?
1.
An attractive and promiscuous girl, small enough to fit in one's pocket. In times of need, she can be removed from the pocket, when she becomes a waitress, by adding a tray, an apron, a socially unacceptable temper, and, potentially, a drug habit.
"The bar was so busy that I had to borrow my friend's pocket waitress!"
See