Source : Webster's Revised Unabridged Dictionary (1913)

Pyrazine \Pyr"a*zine\, n. Also -zin \-zin\ . [Pyridine + Gr. ?
   not + ? life.] (Org. Chem.)
   A feebly basic solid, {C4H4N2}, obtained by distilling
   piperazine with zinc dust, and in other ways. Also, by
   extension, any of various derivatives of the same.