Blockade (5)
'blockade' is the definition.
(I know that siege is a type of blockade)
This is the entire clue.
(Other definitions for siege that I've seen before include "Isolating attack" , "Act of surrounding a town or fortress" , "Military operation ringing a town" , "Offence in which fortified place is surrounded" , "Starving-out operation" .)
'blockade' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for embargo that I've seen before include "Commercial break" , "Trading ban" , "Government trade ban" , "Ban or restraint on trade" , "Boycott" .)
(Other definitions for barrier that I've seen before include "Rear rib may present obstacle" , "'Blockade, fence (7)'" , "block" , "Fence; obstacle" , "Gate" .)