Definition of: shelf

(shelf) noun plural shelves (shelvz)
1. A board or slab set horizontally into or against a wall to support articles, as books; one of the boards in a bookcase or closet; the contents of a shelf.
2. Any flat projecting ledge, as of rock.
3. A steep–sided bank or shallow place in a body of water; a reef; shoal.
4. The stratum of bedrock met in sinking a shaft.
—on the shelf No longer in use; discarded. [<LG schelf set of shelves]