A layered Margarita is three different flavors of frozen Margarita layered one on top of the other to make a rainbow effect.
They have them at the Margarita stand in Mexico(Epcot). It's not the Margarita stand that's attached to Cantina San Angel, but a little farther down, almost to the Norway border.
I think I'll have one tomorrow (she said, rubbing it in )