noun / verb
louver
LOO-ver/ˈluvər/
An angled ventilation slat or vent, or to fit something with these.
The angled louvers let fresh air in while keeping rain out.

Etymology
Old French lovier has an uncertain deeper origin. The English word first named a rooftop structure that dispersed smoke and admitted light, then overlapping slats that let air through while keeping rain out.
In context
a custommade louver vent
More examples
- A small louver provides ventilation near the top of the door.
- Dust collects along the louvers in the attic vent.
- We louver the cabinet doors to keep the electronics cool.
Forms
louver · louvers · louvered · louvering
Similar words
- vent
- Any opening for airflow; need not contain angled slats.
- grille
- A covering of bars or mesh, not necessarily angled slats.