What is "sacellum"

Sacellum \Sa*cel"lum\, n.; pl. Sacella. [L., dim. of sacrum a sacred place.]

1. (Rom. Antiq.) An unroofed space consecrated to a divinity.

2. (Eccl.) A small monumental chapel in a church.
   --Shipley.

n. 1 A small chapel, as a monument within a church 2 (''ancient Rome'') A shrine open to the sky, sometimes used for sacrificial purposes, or in honor of the divine

In ancient Roman religion, a sacellum is a small shrine. The word is a diminutive from sacer ("belonging to a god"). The numerous sacella of ancient Rome included both shrines maintained on private properties by families, and public shrines. A sacellum might be square or round.

Varro and Verrius Flaccus describe sacella in ways that at first seem contradictory, the former defining a sacellum in its entirety as equivalent to a cella, which is specifically an enclosed space, and the latter insisting that a sacellum had no roof. "Enclosure," however, is the shared characteristic, roofed over or not. "The sacellum," notes Jörg Rüpke, "was both less complex and less elaborately defined than a temple proper."

The meaning can overlap with that of sacrarium, a place where sacred objects (sacra) were stored or deposited for safekeeping. The sacella of the Argei, for instance, are also called sacraria. In private houses, the sacrarium was the part of the house where the images of the Penates were kept; the lararium was a form of sacrarium for the Lares. Both sacellum and sacrarium passed into Christian usage.

Other Latin words for temple or shrine are aedes, aedicula, fanum, delubrum and templum, though this last word encompasses the whole religiously sanctioned precinct.