noun
herbicide; weed killer
A chemical agent used to kill unwanted plants; common in agricultural and gardening contexts.
庭の雑草を取るために除草剤を使った。
I used herbicide to remove the weeds in the garden.
この除草剤は環境に優しい成分で作られている。
This herbicide is made with environmentally friendly ingredients.
農薬 is a broader term for agricultural chemicals, including herbicides, insecticides, and fungicides.
Compound of 除 (じょ, 'remove'), 草 (そう, 'grass/weed'), and 剤 (ざい, 'agent/chemical').