What is "saggar"

Seggar \Seg"gar\, n. [Prov. E. saggard a seggar, seggard a sort of riding surtout, contr. fr. safeguard.] A case or holder made of fire clay, in which fine pottery is inclosed while baking in the kin. [Written also saggar, sagger, and segger.]
--Ure.

n. 1 A ceramic container used inside a fuel-fired kiln to protect pots from the flame. 2 fireclay used to make ceramic casings.

A saggar is a type of kiln furniture. It is ceramic, boxlike container used in the firing of pottery to enclose or protect ware being fired inside a kiln. Traditionally, saggars were made primarily from fireclay. Saggars have been used to protect, or safeguard, ware from open flame, smoke, gases and kiln debris: the name is a contraction of the word safeguard. Their use is widespread, including in China, Korea, Japan and the United Kingdom. Saggars are still used in the production of ceramics to shield ware from the direct contact of flames and from damage by kiln debris. Modern saggars are made of alumina ceramic, cordierite ceramic, mullite ceramic and silicon carbide.