'Shelf' definitions:

Definition of 'shelf'

From: WordNet
noun
A support that consists of a horizontal surface for holding objects
noun
A projecting ridge on a mountain or submerged under water [syn: ledge, shelf]

Definition of 'Shelf'

From: GCIDE
  • Shelf \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. [1913 Webster]
  • 2. A sand bank in the sea, or a rock, or ledge of rocks, rendering the water shallow, and dangerous to ships. [1913 Webster]
  • On the tawny sands and shelves. --Milton. [1913 Webster]
  • On the secret shelves with fury cast. --Dryden. [1913 Webster]
  • 3. (Mining) A stratum lying in a very even manner; a flat, projecting layer of rock. [1913 Webster]
  • 4. (Naut.) A piece of timber running the whole length of a vessel inside the timberheads. --D. Kemp. [1913 Webster]
  • To lay on the shelf, to lay aside as unnecessary or useless; to dismiss; to discard. [1913 Webster]