Embargoes (4)
'embargoes' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bans that I've seen before include "Prohibiting decree" , "Forbids" , "Officially prohibits" .)
(Other definitions for boycotts that I've seen before include "Refuses to have anything to do with, ostracises" , "Refuses to have anything to do with, perhaps in business (8)" , "Sends to Coventry, won't do business with" , "Refuses to have anything to do with, perhaps in trade" , "Refuses to trade with or recognise" .)