cafetorium

noun

1. A large room, usually in a school, used as both a cafeteria and an auditorium.

   “There is another combination which is regarded favorably, particularly where economy of space is a necessity. This is the combined cafeteria-auditorium unit and is often called a cafetorium or an auditeria.”

   “Then Mitchell reminded his mother that they both needed money to pay for their lunches, which meant a search for the exact change to pay for two lunches so they would not slow up the line in the cafetorium.”