1[countableC, uncountableU]PROTECT when someone goes around different parts of an area at regular times to check that there is no trouble or danger 巡逻,巡查
on patrol
police on patrol in the city centre
在市中心巡逻的警察
The security forces increased their patrols in the area.
patrol boat/car• There will already be a couple of chaps in a patrol car down a side street as a matter of course.• When Lombardy left home about 8 a.m., the detective followed and alerted an officer in a patrol car.• But lifeguards on a patrol boat sent to the area could not locate the whale.• Another had himself chauffeured around in patrol cars.• Consequently, the riders were escorted to the state line where Mississippi patrol cars took over.• Instead they took the kids away in the patrol car and told me to wait.• Despite the protection of the reef, there was sufficient sea running to make the patrol boatroll through sixty degrees.• Their lead over the patrol boat was down to two hundred yards.
Originpatrol1
(1600-1700)Frenchpatrouiller, from patte“animal's foot”