Abbreviation for Performing Arts Center, a pretentious euphemism for an auditorium. Used mainly by elitist administrators who know little or nothing about the intricate workings of any type of performing arts.
Administrator: And here, we have the PAC, our main facility for, uh... Performing arts.
Citizen: Oh, and what production is the department currently working on?
Administrator: Production? Um... Oh, and over here we have the commons area.
Citizen: It's a CAFETERIA, you pretentious bastard!