B1
an area where a particular thing happens, that is used for a particular purpose, or where there are particular rules
Dictionary examples:
The office has a 'no-singing zone', but I still hum quietly. (0.0)
The school cafeteria has a 'no-broccoli zone' because kids kept throwing it. (0.0)
My kitchen is a 'no-diet zone'. Cookies always win here! (0.0)
a nuclear-free zone (28.1)
an earthquake zone (32.0)
The UN Security Council has established a no-fly zone. (34.8)
He was charged with driving 75 mph in a 55 mph zone. (85.2)