pyrethrum

py·re·thrum  (p-rthrm, -rthrm)

n.

1. Any of several Old World plants of the genus Chrysanthemum, such as C. coccineum, cultivated for their showy flower heads.

2. An insecticide made from the dried flower heads of Chrysanthemum cinerariifolium or C. coccineum.

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[Latin, pellitory, from Greek purethron, feverfew, from pr, fire (from its warming effect); see pyretic.]

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pyrethrum [pie-reeth-rum]

Noun

1. a Eurasian chrysanthemum with white, pink, red, or purple flowers

2. an insecticide prepared from dried pyrethrum flowers [Greek purethron]

Thesaurus

Noun	1.	pyrethrum - made of dried flower heads of pyrethrum plants insect powder, insecticide - a chemical used to kill insects
	2.	pyrethrum - white-flowered pyrethrum of Balkan area whose pinnate leaves are white and silky-hairy below; source of an insecticide; sometimes placed in genus Chrysanthemum Chrysanthemum cinerariifolium, Dalmatia pyrethrum, Dalmatian pyrethrum, Tanacetum cinerariifolium genus Tanacetum, Tanacetum - a large genus of plants resembling chrysanthemums; comprises some plants often included in other genera especially genus Chrysanthemum herb, herbaceous plant - a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests
	3.	pyrethrum - 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 Chrysanthemum coccineum, painted daisy, Tanacetum coccineum flower - a plant cultivated for its blooms or blossoms genus Tanacetum, Tanacetum - a large genus of plants resembling chrysanthemums; comprises some plants often included in other genera especially genus Chrysanthemum
	4.	Pyrethrum - used in former classifications for plants later placed in genus Chrysanthemum and now often included in genus Tanacetum genus Pyrethrum asterid dicot genus - genus of more or less advanced dicotyledonous herbs and some trees and shrubs aster family, Asteraceae, Compositae, family Asteraceae, family Compositae - plants with heads composed of many florets: aster; daisy; dandelion; goldenrod; marigold; lettuces; ragweed; sunflower; thistle; zinnia