What is Cordon ?
Cordon is (noun) 1. a barrier such as a rope or a line of police or soldiers surrounding an area to prevent people entering or leaving Police formed a cordon round the referee to protect him from the fans. There was a police cordon round the courthouse. 2. a fruit tree grown as a single stem, with little side shoots We planted a cordon pear against the wall.(verb) to cordon off a street to block a street to prevent anyone entering it The police had cordoned off the side streets and forced the protesters to march down the main road.
source: Easier English, Student Dictionary Upper Intermediate Level