duty-free store; duty-free shop
A store where goods are sold without certain local or national taxes, typically for travelers.
空港の免税店でお土産を買った。
I bought souvenirs at the duty-free shop in the airport.
免税店で買い物をするにはパスポートが必要です。
You need a passport to shop at a duty-free store.
I bought perfume at the airport's duty-free shop.
I stopped by the duty-free shop before flying home.