Louvre

Concise Oxford English Dictionary © 2008 Oxford University Press:
louvre /ˈluːvə/ (US also louver)

▶noun

• 1 each of a set of angled slats fixed at regular intervals in a door, shutter, or cover to allow air or light through.

• 2 (in a medieval house) a structure in a roof incorporating openings for the passage of smoke.

– derivatives
louvred adjective.

– origin ME: from OFr. lover, lovier ‘skylight’, prob. of Gmc origin and rel. to lodge.