a strongly poisonous crystalline base, (NH)C:NH, normally found in the urine as a result of protein metabolism
See guanidine in American Heritage Dictionary 4
(gwäˈnĭ-dēnˌ)
noun
A strongly alkaline crystalline compound, NHC(NH2)2, formed by the oxidation of guanine and found in the urine as a normal product of protein metabolism. It is commonly used in the organic synthesis of plastics, resins, and explosives.