sulfuric acid

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

• noun A highly corrosive, dense, oily liquid, H₂SO₄, colorless to dark brown depending on its purity and used to manufacture a wide variety of chemicals and materials including fertilizers, paints, detergents, and explosives.

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

• noun inorganic chemistry A transparent, oily liquid, formula H2SO4, that is a strong acid with very many industrial applications.

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

• noun (H2SO4) a highly corrosive acid made from sulfur dioxide; widely used in the chemical industry