1.
an insecticide effective especially against malaria-carrying mosquitoes. It has been banned in many countries since 1974 because of its toxicity, its persistence in the environment, and its ability to accumulate in living tissue.
2.
a poisonous chemical used for killing insects that destroy cropsIt also kills animals and is dangerous to humans, so is no longer allowed in many countries. This kind of chemical is called a pesticide or an insecticide.