noun

a line or circle of police, soldiers, or guards preventing access to or from an area or building.

the crowd was halted in front of the police cordon

barrier,line,column,row,file,ranks,chain,ring,circle,picket line,crocodile

verb

prevent access to or from an area or building by surrounding it with police or other guards.

the city centre was cordoned off after fires were discovered in two stores

close off,seal off,tape off,fence off,rope off,screen off,curtain off,shut off,partition off,separate off,isolate,segregate,quarantine,seal,close,shut,blockade,enclose,encircle,surround