storm window

American  

noun

1. a supplementary window sash for protecting a window against drafts, driving rain, etc.

---

storm window British  

noun

1. an additional window fitted to the outside of an ordinary window to provide insulation against wind, cold, rain, etc

2. a type of dormer window

---

Etymology

Origin of storm window

First recorded in 1885–90

Example Sentences

“The storm window is open,” Hall said, adding that the continuous soggy forecast is “a rare pattern we get to see every once in a while.”

From Los Angeles Times • Dec. 30, 2022

From inside, you would see a little of the storm window frame, but you would still have almost all of the light that you get now.

From Washington Post • Dec. 4, 2020

The existing single-glazed windows were bi-glazed, and with the addition of an interior storm window, they essentially became triple-glazed, said Mr. Scully, the architect who supervised on site.

From New York Times • Aug. 6, 2014

Cost of materials for an average-size, null storm window: about $8.

From Time Magazine Archive

As quietly as I could, I removed the screen from my window, set it against the wall, climbed into the flowerbed outside, and slid the storm window shut behind me.

From "Made You Up" by Francesca Zappia