Pesticide means any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest, or intended for use as a plant regulator, defoliant, or desiccant, other than any article that:
(1) Is a new animal drug under FFDCA section 201(w), or
(2) Is an animal drug that has been determined by regulation of the Secretary of Health and Human Services not to be a new animal drug, or
(3) Is an animal feed under FFDCA section 201(x) that bears or contains any substances described by paragraph (1) or (2) of this definition.
40 CFR § 260.10
When used in parts 260 through 273 of this chapter, the following terms have the meanings given below: