any chemical compound with a molecular structure consisting of four atoms of carbon and two of nitrogen, arranged in a ring; esp., any of the three isomeric compounds having the formula CHN
See diazine in American Heritage Dictionary 4
(dīˈə-zēnˌ, dī-ăzˈĭn)
noun
A compound containing a benzene ring in which two of the carbon atoms have been replaced by nitrogen atoms, especially any of three isomers having the composition C4H4N2.