violuric

from The Century Dictionary.

• Noting an acid (nitrosobarbituric acid), a yellowish compound, prepared by the action of potassium nitrite on barbituric acid. It forms lustrous, trimetric crystals.

from the GNU version of the Collaborative International Dictionary of English.

• adjective (Chem.) Of, pertaining to, or designating, a complex nitroso derivative of barbituric acid. It is obtained as a white or yellow crystalline substance, and forms characteristic yellow, blue, and violet salts.