English
cyanogen
From cyano- + -gen; compare French cyanogène.
Formed from cyano + gen
The story
So called because it produced blue dyes.
Today it means
noun The pseudohalogen (CN)₂; a colorless, poisonous gas used as a rocket propellant, an insecticide and in chemical warfare.
Language periods are conventional ranges, not dates for this word.
Etymograph / cyanogen