dual

雙重的、兩種的

She holds dual citizenship and travels with two passports.

她擁有雙重國籍，出國時帶著兩本護照。

兩用的、雙功能的

This room serves a dual purpose as an office and a guest bedroom.

這個房間兼作辦公室和客房，具有兩用功能。

雙的、成對的

The car has dual airbags on the driver's side.

這輛車在駕駛座一側裝有雙氣囊。

雙數語法

Ancient Greek had a dual as well as a singular and a plural.

古希臘文除了單數和複數之外還有雙數。