a powerful insecticide (ClCH)CHCCl, effective upon contact: its use is restricted by law due to damaging environmental effects
See DDT in American Heritage Dictionary 4
(dēˌdē-tēˈ)
noun
A colorless contact insecticide, C14H9Cl5, toxic to humans and animals when swallowed or absorbed through the skin. It has been banned in the United States for most uses since 1972.