/
ˈkɔːd(ə)n/
n.
   - a line or circle of police, soldiers, or guards preventing access to or from a place.
 - a fruit tree trained to grow as a single stem.
 - Architecture  another term for string course.
 
v.
 
(
cordon something off)
 prevent access to or from a place by means of a cordon.
Etymology
ME: from Ital. cordone, augmentative of corda, and Fr. cordon, dimin. of corde, both from L. chorda (see cord).