Piperazine \Pi*per"a*zine\, n. Also -zin \-zin\ . [Piperidine + azote + -ine.] (Chem.) A crystalline substance, {(C2H4NH)2}, formed by action of ammonia on ethylene bromide, by reduction of pyrazine, etc. It is a strong base, and is used as a remedy for gout.