pyrethrum
Americannoun
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any of several chrysanthemums, as Chrysanthemum coccineum, having finely divided leaves and showy red, pink, lilac, or white flowers, cultivated as an ornamental.
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any of several chrysanthemums, as C. cinerariifolium, or C. coccineum, cultivated as a source of insecticides.
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Pharmacology. the dried flower heads of these plants, used chiefly as an insecticide and sometimes in medicine for certain skin disorders.
noun
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any of several cultivated Eurasian chrysanthemums, such as Chrysanthemum coccineum and C. roseum, with white, pink, red, or purple flowers
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any insecticide prepared from the dried flowers of any of these plants, esp C. roseum
Etymology
Origin of pyrethrum
First recorded in 1555–65; from Latin, from Greek pýrethron, the name of the flower, akin to pyretós “fever”
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Lives can be spared by applying insect repellents, including a chrysanthemum flower extract called pyrethrum that humans have used for thousands of years.
From Scientific American ● Aug. 18, 2021
The Documentary category was won by Vito Fusco, of Italy, for his series on Kenya's pyrethrum flowers, which are used as a natural insecticide.
From BBC ● Apr. 15, 2021
"During the 1980s, the pyrethrum crisis began, instigated by the chemical synthesis of pyrethroids that led to the manufacturing of cheaper but non-organic products," he said.
From BBC ● Apr. 15, 2021
A good example is the distinction between natural pyrethrum and synthetic pyrethroids.
From Scientific American ● Aug. 15, 2011
These George picked off, but he found that he could not keep up with them; so The Chief advised him to buy a little pyrethrum powder at the store.
From The Library of Work and Play: Gardening and Farming. by Shaw, Ellen Eddy
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
