1.NounAn organophosphorus insecticide used to control fleas etc. [O,O-Diethyl O-[4-methyl-6-(propan-2-yl)pyrimidin-2-yl]
"" Diazinon is an insecticide and acaricide with stomach poison and contact activity. It has a wide range of pest-control applications and has long residual effects.""