hydrazine /ˈhaɪdɹəˌziːn/ noun2 •A corrosive, fuming liquid, NH₂-NH₂, used as a rocket fuel. •Any member of the class of organic compounds formally derived from NH₂-NH₂ by replacing one of the hydrogen atoms.From ethyleneoxides or ethyleneimines carrying an acyl substituent, with hydrazine and its derivatives (Ch. 3. XV). — 2009 formshydrazines