1. A support that consists of a horizontal surface for holding objects
   "She arranged her books neatly on the shelf"
    
2. A projecting ridge on a mountain or submerged under water
   "he came dangerously close to falling off the shelf";
   - ledge

Type of: ridge, support

Part of: bookcase, buffet, bureau [N. Amer], cabinet, chest, chest of drawers, closet, counter, dresser [N. Amer], etagere, étagère, food market, grocery, grocery store, market, mart, sideboard

Encyclopedia: Shelf, West Yorkshire