sweep room
n.— «Also at Lanphier, beginning Monday, administrators will make sweeps of the hallways when the bell rings at the beginning of the first morning class and the first afternoon class. Teachers will close their classroom doors when class begins, and administrators will herd any laggards caught in hallways or restrooms to a designated “sweep room.”» —“Lanphier’s unpopular ‘sweeps’ ; Students balk at measure to clear hallways on time” by Lisa Kernek State Journal-Register (Springfield, Illinois) Jan. 21, 2000. (source: Double-Tongued Dictionary)