/huy"dreuh zeen'/ , n.
1. Also called diamine . a colorless, oily, fuming liquid, N 2 H 4 , that is a weak base in solution and forms a large number of salts resembling ammonium salts: used chiefly as a reducing agent and a jet-propulsion fuel.
2. a class of substances derived by replacing one or more hydrogen atoms in hydrazine by an organic group.
[ 1885-90; HYDR- 2 + AZ- + -INE 2 ]