A hard white amorphous powder, ZrO2, derived from zirconium and also found naturally, used chiefly in pigments, refractories, and ceramics and as an abrasive.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.