\Shelf\, n.; pl. {Shelves}. [OE. shelfe, schelfe, AS.
scylfe; akin to G. schelfe, Icel. skj[=a]lf. In senses 2 & 3,
perhaps a different word (cf. {Shelve}, v. i.).]
1. (Arch.) A flat tablet or ledge of any material set
   horizontally at a distance from the floor, to hold objects
   of use or ornament.
2. A sand bank in the sea, or a rock, or ledge of rocks,
   rendering the water shallow, and dangerous to ships.
         On the tawny sands and shelves.       --Milton.
         On the secret shelves with fury cast. --Dryden.
3. (Mining) A stratum lying in a very even manner; a flat,
   projecting layer of rock.
4. (Naut.) A piece of timber running the whole length of a
   vessel inside the timberheads. --D. Kemp.
{To lay on the shelf}, to lay aside as unnecessary or
   useless; to dismiss; to discard.