noun
chemical warfare
Refers to the use of chemical substances as weapons in war.
化学戦の歴史は第一次世界大戦にさかのぼる。
The history of chemical warfare dates back to World War I.
Poison gas, a common agent used in chemical warfare.
Compound of 化学 (かがく, 'chemistry') and 戦 (せん, 'warfare').