duty-free       
 adjective uk/ˌdʒuː.tiˈfriː/ us/ˌduː.t̬iˈfriː/
B1 (商品)免税的
Duty-free goods are goods bought in special shops in airports, on ships, etc. on which you do not pay government tax.
  He bought his wife some duty-free perfume. 他给妻子买了一些免税香水。 
 I bought some perfume in the duty-free shop. 我在免税店买了一些香水。 
 duty-free          
noun uk/ˌdʒuː.tiˈfriː/ us/ˌduː.t̬iˈfriː/
 [ U ](在机场或船上等的)免税商品 
goods that you can buy in special shops in airports, on ships, etc., without paying tax on them
  We can buy our duty-free while we're waiting at the airport. 我们在机场候机时可以买些免税商品。 
  [ C ] (also duty-free shop)(在机场或船上等的)免税商店 
a shop at an airport, on a ship, etc. where you can buy duty-free goods
  There'll be a duty-free on the ferry. 轮船上有免税商店。