sandbox
n.— «The sergeant isn’t excited about war in the desert, but he isn’t sure that peace in the desert is a whole lot safer.…He had just three days to do laundry and convalesce before heading back into the sandbox.» —“Maps from St. Paul should help” by Jim Klobuchar Star-Tribune (Minneapolis and St. Paul, Minn.) Sept. 22, 1990. (source: Double-Tongued Dictionary)