/raht"skel'euhr, rat"-, rath"-/ , n.
1. (in Germany) the cellar of a town hall, often used as a beer hall or restaurant.
2. a restaurant patterned on the German rathskeller, usually located below street level.
[ 1860-65; Rath (extracted from Rathaus town hall) + -s 's 1 + Keller CELLAR ]