dichlorodiphenyltrichloroethane /ˌdaɪˌklɔːroʊˌdaɪˌfɛnəlˌtraɪˌklɔːroʊˈɛθeɪn/ noun1 •A long-lasting synthetic insecticide formerly used to kill mosquitoes and crop pests. It became controversial because it persists in the environment and harms wildlife by building up in food chains. formsdichlorodiphenyltrichloroethanes