any of a family of heterocyclic hydrocarbons; esp., any of a number of isomers of a highly toxic chlorinated teratogen, TCDD, that occurs as an impurity in some herbicides and defoliants, including trichlorophenoxyacetic acid, a component of Agent Orange
Origin:
di- + ox- + -in
See dioxin in American Heritage Dictionary 4
noun
Any of several carcinogenic or teratogenic heterocyclic hydrocarbons that occur as impurities in petroleum-derived herbicides.