chromic acid

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

• noun A corrosive, oxidizing acid, H₂CrO₄, occurring only as salts or in solution.
• noun The anhydride of chromic acid, CrO₃, a purplish crystalline material that reacts explosively with reducing agents and is used in chromium plating, as an oxidizing agent, and to color glass and rubber.

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

• noun inorganic chemistry A corrosive acid, H2CrO4, known only in solution or as its salts, the chromates (from which it may be prepared); it is a very powerful oxidizing agent.

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

• noun an unstable acid known only in solution and as chromate salts