Assume importing gold will be strange (7)
I believe the answer is:
foreign
'strange' is the definition.
('foreign' can be similar in meaning to 'strange')
'assume importing gold' is the wordplay.
'assume' becomes 'feign' ('feign' can be a synonym of 'assume').
'importing' is an insertion indicator.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'feign' going around 'or' is 'FOREIGN'.
'will be' is the link.
(Other definitions for foreign that I've seen before include "Concerning other nations" , "Of or from another country" , "not typical" , "Alien" , "Exotic" .)