Pyrethron

Part of speech: noun

Definitions

1. A flowering plant of the genus Chrysanthemum, native to the Caucasus, whose dried flowers contain natural compounds toxic to insects ; a pesticide made from the powdered flowers of this plant, used to kill or repel insects
2. A daisy-like perennial herb yielding insect-killing substances in its flower heads ; an organic insecticide extracted from these flowers and applied to control household and agricultural pests
3. A plant bearing daisy-shaped blooms that possess inherent insecticidal properties ; an insecticide manufactured from the dried flower material of this plant and employed against various pest species

Etymology: The Greek "pyrethron" named a pungent plant, and its root points to "pyr," meaning fire. The name most likely refers to the plant's burning, peppery taste, which Greek and Roman writers noted. Its Greek relative "pyretos," meaning fever, shares the same root, but the link between the plant and fever is uncertain. The Latin "pyrethrum" carried the name into scientific writing, and English adopted it for the plant. The name later moved to a different plant entirely. The pyrethrum now familiar from insect sprays is a daisy-like flower whose petals contain insecticidal compounds called pyrethrins, so the name shifted from a medicinal herb to a pesticide source.