dieldrin Syllabification: (diel·drin)Pronunciation: /ˈdēldrin/Definition of dieldrin noun a toxic insecticide produced by the oxidation of aldrin, now largely banned because of its persistence in the environment. A chlorinated epoxide; chemical formula: C12H8Cl6O Origin: 1940s: blend of the name Diels (see Diels–Alder reaction) + aldrindieldrin in other Oxford dictionaries Definition of dieldrin in the British & World English dictionary
