The Collaborative International Dictionary of English v.0.48:

Cellar \Cel"lar\, n. [OE. celer, OF. celier, F. celier, fr. L.
   cellarium a receptacle for food, pantry, fr. cella storeroom.
   See Cell.]
   A room or rooms under a building, and usually below the
   surface of the ground, where provisions and other stores are
   kept.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cellar
    n 1: the lowermost portion of a structure partly or wholly below
         ground level; often used for storage [syn: basement,
         cellar]
    2: an excavation where root vegetables are stored [syn: root
       cellar, cellar]
    3: storage space where wines are stored [syn: cellar, wine
       cellar]

Moby Thesaurus II by Grady Ward, 1.0:

66 Moby Thesaurus words for "cellar":
   archives, armory, arsenal, attic, bank, basement, bay, bin,
   bonded warehouse, bookcase, box, bunker, buttery, cargo dock,
   cellarage, chest, closet, coal bin, conservatory, crate, crib,
   cupboard, cyclone cellar, depository, depot, dock, drawer, dump,
   exchequer, glory hole, godown, hold, hole, hutch, library, locker,
   lumber room, lumberyard, magasin, magazine, potato cellar, rack,
   repertory, repository, reservoir, rick, shelf, stack, stack room,
   stock room, storage, store, storehouse, storeroom, storm cellar,
   subbasement, supply base, supply depot, tank, treasure house,
   treasure room, treasury, vat, vault, warehouse, wine cellar



Easton's 1897 Bible Dictionary:

Cellar
   a subterranean vault (1 Chr. 27:28), a storehouse. The word is
   also used to denote the treasury of the temple (1 Kings 7:51)
   and of the king (14:26). The Hebrew word is rendered "garner" in
   Joel 1:17, and "armoury" in Jer. 50:25.