Meaning of ball clay

ball' clay"

Pronunciation: [key]
— Ceram. Ceram.
  1. a fine dark kaolinic clay that turns white or nearly white when fired, used in the manufacture of a wide variety of ceramic wares in combination with other clays for its exceptional bonding properties and plasticity.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.