A pesticide is any substance or mixture of substances intended for:
- repelling, or
- mitigating any pest.
Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests.
Under Philippines law, a pesticide is also any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.