TETRAZIN

Tet*raz"ine, n. Also -in. [Tetrazo- + -ine.] (Chem.)

Definition: A hypothetical compound, C2H2N4 which may be regarded as benzene with four CH groups replaced by nitrogen atoms; also, any of various derivatives of the same. There are three isomeric varieties.

Source: Webster’s Unabridged Dictionary 1913 Edition