transom
🇺🇸
/ˈtrænsəm/
🇬🇧
/ˈtrænsəm/
A horizontal piece of wood or stone that is fixed across the top of a door or window to provide support.
The burglar entered the house through the transom above the front door.
A small window that is placed above a door or another window.
The transom in the bathroom provided some natural light during the day.