window
/ˈwɪndoʊ/·윈도우·noun
an opening in a wall to let in light or air
NorseCEFR A1
Root
Old Norse 'vindauga' (wind + eye)
Old Norse vindauga (literally 'wind-eye') → Middle English wyndowe → Modern window
In a word
Old Norse vindauga = 'wind-eye'. Before glass, an opening in a wall was where the wind came in and where you looked out — quite literally a wind-eye. The Vikings carried the poetic name to England, and it stayed. Even your computer's "Windows" is heir to that ancient wind-eye.
Examples
Please open the window.
The cat sat by the window.
Rain ran down the window glass.
Related
windowsillwindowpaneshop-window