pyrethrum

noun

py·​re·​thrum pī-ˈrē-thrəm  -ˈre- 

1

: any of several chrysanthemums with finely divided often aromatic leaves including ornamentals as well as important sources of insecticides

2

: an insecticide made from the dried heads of any of several Old World chrysanthemums (especially Chrysanthemum cinerariaefolium)

Examples of pyrethrum in a Sentence

Recent Examples on the Web

To observe pyrethrum’s effects, Dong and her colleagues attached tiny electrodes to hairs on mosquitoes’ antennae. — Rachel Nuwer, Scientific American, 19 July 2021

Lives can be spared by applying insect repellents, including a chrysanthemum flower extract called pyrethrum that humans have used for thousands of years. — Rachel Nuwer, Scientific American, 19 July 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. — Cecilia Rodriguez, Forbes, 4 Mar. 2021

The pyrethrum is known as the ‘flower of death’ – a nickname that neatly describes this delicate daisy imbued with murderous power. — Cecilia Rodriguez, Forbes, 4 Mar. 2021

The pyrethrum is cultivated mainly in the hills of Nakuru in Kenya and is the arch foe of the insect world. — Cecilia Rodriguez, Forbes, 4 Mar. 2021

Word History

Etymology

Latin, pellitory, from Greek pyrethron, from pyr fire

First Known Use

circa 1543, in the meaning defined at sense 1

Rhymes for pyrethrum

• callosum
• nodosum
• overcome
• saccharum
• abomasum
• become
• checksum
• humdrum
• income
• outcome
• pisum
• succumb

Kids Definition

pyrethrum

noun

py·​re·​thrum pī-ˈrē-thrəm  -ˈreth-rəm 

1

: any of several chrysanthemums that have finely divided leaves and include ornamental plants as well as important sources of insecticides

2

: an insecticide consisting of the dried heads of some Old World pyrethrums

Medical Definition

pyrethrum

noun

py·​re·​thrum pī-ˈrē-thrəm  -ˈreth-rəm 

1

: any of several chrysanthemums with finely divided often aromatic leaves including ornamentals as well as important sources of insecticides

2

: an insecticide consisting of or derived from the dried heads of any of several Old World chrysanthemums (genus Chrysanthemum of the family Asteraceae)