Embargo (7)
'embargo' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for boycott that I've seen before include "Refuse to deal with - Yorkshire and England batsman" , "Refuse to handle or deal with" , "Refuse to deal with - outlaw" , "Refuse to do business with" , "Ostracise" .)
'embargo' is the definition.
(a ban on trade)
This is the entire clue.
(Other definitions for ban that I've seen before include "the calling of young vassals" , "Officially prohibit" , "'Forbid, prohibit (3)'" , "Exile" , "Bar, prohibition" .)