potassium chloride

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

• noun A colorless crystalline solid or powder, KCl, used widely in fertilizers and in the preparation of most potassium compounds.

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

• noun inorganic chemistry The potassium salt of hydrochloric acid, KCl; it is used as a fertilizer, and in lethal injections

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

• noun salt of potassium (KCl) (trade names K-Dur 20, Kaochlor and K-lor and Klorvess and K-lyte); taken in tablet form to treat potassium deficiency