二に重じゅう窓まど

noun

double window; double-glazed window; storm window

Refers to a window with two layers, either for insulation (double glazing) or as an additional outer window (storm window).

• 寒さむい地ち域いきでは、二に重じゅう窓まどが断だん熱ねつに役やく立だつ。

  In cold regions, double-glazed windows help with insulation.

• この家いえは二に重じゅう窓まどになっているので、外そとの音おとがほとんど聞きこえない。

  This house has double windows, so you can hardly hear outside noise.