aldrinPronunciation: /ˈɔːldrɪn/Definition of aldrin noun [mass noun] a toxic synthetic insecticide, now generally banned. A chlorinated polycyclic hydrocarbon; chemical formula: C12H8Cl6 Origin: 1940s: from the name of K. Alder (see Diels–Alder reaction) + -in1aldrin in other Oxford dictionaries Definition of aldrin in the US English dictionary