pyrethrum

[ pahy-ree-thruhm, -reth-ruhm ]

/ paɪˈri θrəm, -ˈrɛθ rəm /

noun

any of several chrysanthemums, as Chrysanthemum coccineum, having finely divided leaves and showy red, pink, lilac, or white flowers, cultivated as an ornamental.

any of several chrysanthemums, as C. cinerariifolium, or C. coccineum, cultivated as a source of insecticides.

Pharmacology. the dried flower heads of these plants, used chiefly as an insecticide and sometimes in medicine for certain skin disorders.

Origin of pyrethrum

First recorded in 1555–65; from Latin, from Greek pýrethron, the name of the flower, akin to pyretós “fever”

Words nearby pyrethrum

Pyrénées-Orientales, pyrenocarp, pyrenoid, pyrethrin, pyrethroid, pyrethrum, pyretic, pyreto-, pyretogenesis, pyretogenic, pyretotherapy

Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for pyrethrum

The pyrethrum may be used dry or in water, at the rate of a tablespoonful to two gallons.
Farm Gardening with Hints on Cheap Manuring|Anonymous
The remedy prescribed is a powder in which pyrethrum is the chief ingredient, sprinkled about the shelves.
A Book for All Readers|Ainsworth Rand Spofford
Howard recommends thoroughly rubbing into the fur a quantity of pyrethrum powder.
Handbook of Medical Entomology|William Albert Riley
Pyrethrum is also used largely, but it only stupefies the mosquitoes temporarily instead of killing them.
Insects and Diseases|Rennie W. Doane

The pyrethrum powder is considered the best for this purpose, but is expensive and difficult to procure in the pure state.
The Dollar Hen|Milo M. Hastings

British Dictionary definitions for pyrethrum

pyrethrum

/ (paɪˈriːθrəm) /

noun

any of several cultivated Eurasian chrysanthemums, such as Chrysanthemum coccineum and C. roseum, with white, pink, red, or purple flowers

any insecticide prepared from the dried flowers of any of these plants, esp C. roseum

Word Origin for pyrethrum

C16: via Latin from Greek purethron feverfew, probably from puretos fever; see pyretic

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

单词	pyrethrum
释义	pyrethrum [ pahy-ree-thruhm, -reth-ruhm ] / paɪˈri θrəm, -ˈrɛθ rəm / noun any of several chrysanthemums, as Chrysanthemum coccineum, having finely divided leaves and showy red, pink, lilac, or white flowers, cultivated as an ornamental. any of several chrysanthemums, as C. cinerariifolium, or C. coccineum, cultivated as a source of insecticides. Pharmacology. the dried flower heads of these plants, used chiefly as an insecticide and sometimes in medicine for certain skin disorders. Origin of pyrethrum First recorded in 1555–65; from Latin, from Greek pýrethron, the name of the flower, akin to pyretós “fever” Words nearby pyrethrum Pyrénées-Orientales, pyrenocarp, pyrenoid, pyrethrin, pyrethroid, pyrethrum, pyretic, pyreto-, pyretogenesis, pyretogenic, pyretotherapy Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020 Example sentences from the Web for pyrethrum The pyrethrum may be used dry or in water, at the rate of a tablespoonful to two gallons. Farm Gardening with Hints on Cheap Manuring\|Anonymous The remedy prescribed is a powder in which pyrethrum is the chief ingredient, sprinkled about the shelves. A Book for All Readers\|Ainsworth Rand Spofford Howard recommends thoroughly rubbing into the fur a quantity of pyrethrum powder. Handbook of Medical Entomology\|William Albert Riley Pyrethrum is also used largely, but it only stupefies the mosquitoes temporarily instead of killing them. Insects and Diseases\|Rennie W. Doane The pyrethrum powder is considered the best for this purpose, but is expensive and difficult to procure in the pure state. The Dollar Hen\|Milo M. Hastings British Dictionary definitions for pyrethrum pyrethrum / (paɪˈriːθrəm) / noun any of several cultivated Eurasian chrysanthemums, such as Chrysanthemum coccineum and C. roseum, with white, pink, red, or purple flowers any insecticide prepared from the dried flowers of any of these plants, esp C. roseum Word Origin for pyrethrum C16: via Latin from Greek purethron feverfew, probably from puretos fever; see pyretic Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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