Meaning

noun made of dried flower heads of pyrethrum plants

noun white-flowered pyrethrum of Balkan area whose pinnate leaves are white and silky-hairy below; source of an insecticide; sometimes placed in genus Chrysanthemum

noun spring-flowering garden perennial of Asiatic origin having finely divided aromatic leaves and white to pink-purple flowers; source of an insecticide; sometimes placed in genus Chrysanthemum

originFrom Old English pyretre, from (and later reformed after) Latin pyrethrum (in Pliny), from Hellenistic Ancient Greek πύρεθρον (púrethron).

Etymology from Wiktionary, CC BY-SA 3.0