pesticide
n. C / U B2 Upper Intermediate US //ˈpɛstəˌsaɪd// UK //pˈɛstɪsˌaɪd// pes·ti·cide
n. a chemical substance used to kill insects or other small animals that damage crops and plants.
n. a chemical substance used for destroying organisms that are harmful to cultivated plants or to animals.
Farmers use pesticides to protect their crops from insects.
The local government is encouraging organic farming to reduce the amount of pesticide runoff entering the river system.
While these pesticides effectively eliminate invasive beetles, environmentalists worry about their long-term impact on the local bee population and the broader ecological balance.
From pest + -i- + -cide.
Usage
Uncountable when referring to the substance in general; countable when referring to specific types or brands of the chemical.