calcium chloride

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A white deliquescent solid, CaCl₂, used chiefly as a drying agent, antifreeze, and preservative and for controlling dust and ice on roads.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun inorganic chemistry The calcium salt of hydrochloric acid, CaCl2; used as a drying agent and to melt ice on roads.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a deliquescent salt; used in de-icing and as a drying agent