French for a square or rectangular "paving stone" or "cobblestone. " In culinary usage the word refers to: 1. A square or rectangular dessert consisting of several layers of sponge cake filled with buttercream or other filling and coated with frosting; 2. a square-shaped, aspic-coated mousse made of meat, fish or poultry, usually served cold. It can also be made with a sweet mousse.