Noah Webster
Shelf
SHELF, noun plural shelves.
1. A platform of boards or planks, elevated above the floor, and fixed and set on a frame or contiguous to a wall, for holding vessels, utensils, books and the like.
2. A sand bank in the sea, or a rock or ledge of rocks, rendering the water shallow and dangerous to ships.
3. In mining, fast ground; the part of the internal structure of the earth which lies in an even regular form.