cavern/cellar

cellar, n
1. a. In general sense. A storehouse or storeroom, whether above or below ground, for provisions; a granary, buttery, or pantry. Obs. (in later use regional except as merged with specific senses at 1c and 2).
b. fig. A storehouse, repository. Obs.
c. spec. A storeroom for wine, ale, or the like; (hence) the contents of this; = WINE-CELLAR n.
2. a. A room below ground level in a house or other building, typically used for storage.
b. In extended and fig. use. Something likened to a cellar, esp. in being dark, deep, or hidden.
c. N. Amer. Sport (orig. Baseball). The lowest (or a low) position in the rankings of a league or other grouping. Cf. BASEMENT n. Additions.
3. A box, esp. one for holding drinks and glasses; a case of bottles, a cellaret. Obs.



cavern, n.
1. A hollow place under ground; a subterranean (or submarine) cavity; a cave.
The Fr. caverne is the exact equivalent of Eng. cave; F. cave is a subterranean hollow generally, a cellar, etc. In Eng., cave is the ordinary commonplace term, cavern is vaguer and more rhetorical, usually with associations of vastness, or indefiniteness of extent or limits.
2. Applied to the cavity of the ear, the frontal sinus, etc.; also to interstices between particles. Obs.
3. attrib. and Comb., as cavern-door, -house, -pagoda, -temple, well; cavernhold, nonce-wd. after household; cavern-limestone, ‘the carboniferous limestone of Kentucky, so called from the innumerable caves which its hard strata contain’ (Bartlett); cavern-like a.


Definitions, as always, from the OED online. Amusing picture from the first year trip to Paris!

So cellar it is then?