crowning
The operation, and the result, of forming anything with a slight convexity upward. Crowning is practiced in laying floors of broad span, especially to sustain heavy strains, in order to offset the sagging likely to result in time; upon roadways to secure a proper drainage to the gutters. 2. The termination of the upper part of a building by a suitable decorative feature such as a cornice, pediment, or finial. (Sturgis, 1900)