- a perennial plant (Chrysanthemum coccineum) of the composite family, widely grown for the white, pink, red, or purple flower heads
- an insecticide made from the dried flower heads of several Old World chrysanthemums, esp. a species (Chrysanthemum cinerariaefolium) now grown extensively in the U.S.
Origin of pyrethrumModern Latin from Classical Latin from Classical Greek pyrethron, feverfew from pyr, fire
- a. A Eurasian perennial plant (Tanacetum coccineum) in the composite family, cultivated for its colorful flower heads and formerly used as a source of an insecticide. Also called painted daisy .b. A closely related perennial plant (Tanacetum cinerariifolium), commercially cultivated as the source of an insecticide.
- An insecticide made from the dried flower heads of any of these plants.
Origin of pyrethrumLatin pellitory ( Anacyclus pyrethrum ) from Greek purethron from pūr fire (from its warming effect) ; see pyretic .