noun
: one of various flat clay rings so placed in a pottery kiln that they may be withdrawn successively as the firing proceeds, the amount of shrinkage of the ring indicating the intensity of the fire
noun
: one of various flat clay rings so placed in a pottery kiln that they may be withdrawn successively as the firing proceeds, the amount of shrinkage of the ring indicating the intensity of the fire
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012