B1
Duty-free goods are things you can buy and bring into a country without paying tax.
Dictionary examples:
I saved money on duty-free items, then spent it all on airport food! (0.0)
I bought so much duty-free chocolate, I had to buy a new suitcase! (0.0)
My dad loves duty-free shops so much, he books flights just to visit them! (0.0)
I bought some duty-free perfume at the airport. (22.3)