etymology of sconce is from the Latin absconsus, via the French esconce: a word of many meanings, mostly signifying a covering or protection, or, by extension, that which is covered or protected.

The word is closely related to the medieval Dutch schans and the German word Schanze, as used for example in the name of Hitler's military headquarters, the Wolfsschanze. The word Schanze derives originally from the fact that, during sieges