double-action
adjective [ before noun ] uk/ˌdʌb.əlˈæk.ʃən/ us/ˌdʌb.əlˈæk.ʃən/
有双重作用的
having two different purposes
This double-action lotion soothes your skin and enriches your tan. 这种具有双重功效的涂剂既能呵护皮肤还能加深晒成的棕褐色。
（手枪等）联动式击发的
used to refer to a gun that needs one action for preparing to shoot it and one action for shooting it