Insecticide (noun)

A substance or chemical used to kill or control insects.

Origin:

From latin insectum ("insect") + -cide ("killer, destroye.r")

Examples:

1. The farmer sprayed the fields with insecticide to protect the crops.
2. The insecticide was effective in controlling the population of mosquitoes.
3. The gardener used an organic insecticide to protect her plants.
4. The use of insecticide has led to the development of resistant pests.
5. The insecticide was banned due to its negative effects on the environment.