The word "sconce" comes from the Latin absconsus via the French esconce, which means a covering or protection - or something that is covered and protected.
It's also a kind of fortification from the Middle Ages, a protective "hill" which offered defense for artillery units.
Obviously, we don't deal with earthwork castle fortifications. We deal with lighting, and a sconce is a light fitting that uses only the wall for support - it doesn't have a base on the floor.
They are used for functional and decorative purposes, and here are some of our favourites from the online store:
Nordlux Vanila Black Wall Spotlight
Astro Lighting Azumi White Wall Light with a Reading Light

On the one hand, the Azumi is a classically styled wall light from the renowned Astro Lighting, but it also features a flexible LED reading light as a hidden bonus.
Artemide Dioscuri