Definition of pyrethrum in English:

pyrethrum

noun pʌɪˈriːθrəm

1An aromatic plant of the daisy family, typically having feathery foliage and brightly coloured flowers.
除虫菊
Genus Tanacetum (formerly Chrysanthemum or Pyrethrum), family Compositae: several species, in particular T. coccineum, grown as an ornamental, and T. cinerariifolium, grown as a source of the insecticide pyrethrum
Example sentencesExamples
- This is the area where significant cash crops are grown, including pyrethrum (a flower that produces a natural insecticide), coffee and tea.
- When I looked closely I could see the truck had a PyGanic label with the iconic pyrethrum flower on the side.
- Others are synthetic versions of naturally-occurring insecticides, such as those found in the plant pyrethrum.
- In some areas, extremely fertile soils produce coffee, tea, and pyrethrum (used in making insecticides).
- Not all herbs smell good - catmint, curry plant, pyrethrum, rue, santolina and tansy are all pretty pongy.
- Some are derived from plants, such as pyrethrum and neem.
1. 1.1mass noun An insecticide made from the dried flowers of pyrethrum plants.
  除虫菊杀虫剂
  Example sentencesExamples
  Pesticides that are approved for organic farming include copper, sulfur, petroleum distillates, and pyrethrum.
  By the mid 1800s, the heads of chrysanthemum flowers were used to obtain pyrethrum, and rotenone was extracted from the derris plant.
  ‘That's pyrethrum,’ said Niko ‘it's used as an insecticide.’
  Daisy plants were first used centuries ago as a lice remedy in the Middle East, and this led to the discovery of pyrethrum insecticides.
  You can purchase concentrated pyrethrum from a nursery or the garden supply section of your supermarket.
  You can treat them with pyrethrum, white oil, soapy water or just squash them with your fingers.
  A natural pyrethrum insecticide is cheaper, less harmful and just as effective as those chemical poisons to kill spiders.
  Rotenone and pyrethrum don't work, even if applied more frequently.
  It seems probable that in the future, synthetic pyrethroids will be of more interest than pyrethrum as possible delousing agents.
  Adult mosquitoes were obtained from houses within a village by resting and pyrethrum knockdown collections.
  For body lice, use pyrethrum with piperonyl butoxide lotion over the whole body and wash off after 10 minutes.
  The spray does not control the adults, so you can either handpick the adults or spray them with pyrethrum insecticide.
  Geoff reckons to use a contact spray like pyrethrum which breaks down within about 24 hours.

Origin

Middle English (denoting pellitory): from Latin, from Greek purethron 'feverfew'. The current senses (based on the former genus name) date from the late 19th century.

Definition of pyrethrum in US English:

pyrethrum

noun

1An aromatic plant of the daisy family, typically having feathery foliage and brightly colored flowers.
除虫菊
Genus Tanacetum (formerly Chrysanthemum or Pyrethrum), family Compositae: several species, in particular T. coccineum, grown as an ornamental, and T. cinerariifolium, grown as a source of the insecticide pyrethrum
Example sentencesExamples
- Some are derived from plants, such as pyrethrum and neem.
- When I looked closely I could see the truck had a PyGanic label with the iconic pyrethrum flower on the side.
- Others are synthetic versions of naturally-occurring insecticides, such as those found in the plant pyrethrum.
- This is the area where significant cash crops are grown, including pyrethrum (a flower that produces a natural insecticide), coffee and tea.
- Not all herbs smell good - catmint, curry plant, pyrethrum, rue, santolina and tansy are all pretty pongy.
- In some areas, extremely fertile soils produce coffee, tea, and pyrethrum (used in making insecticides).
1. 1.1 An insecticide made from the dried flowers of the pyrethrum plant.
  除虫菊杀虫剂
  Example sentencesExamples
  The spray does not control the adults, so you can either handpick the adults or spray them with pyrethrum insecticide.
  Daisy plants were first used centuries ago as a lice remedy in the Middle East, and this led to the discovery of pyrethrum insecticides.
  Pesticides that are approved for organic farming include copper, sulfur, petroleum distillates, and pyrethrum.
  Adult mosquitoes were obtained from houses within a village by resting and pyrethrum knockdown collections.
  It seems probable that in the future, synthetic pyrethroids will be of more interest than pyrethrum as possible delousing agents.
  By the mid 1800s, the heads of chrysanthemum flowers were used to obtain pyrethrum, and rotenone was extracted from the derris plant.
  ‘That's pyrethrum,’ said Niko ‘it's used as an insecticide.’
  You can treat them with pyrethrum, white oil, soapy water or just squash them with your fingers.
  For body lice, use pyrethrum with piperonyl butoxide lotion over the whole body and wash off after 10 minutes.
  Rotenone and pyrethrum don't work, even if applied more frequently.
  A natural pyrethrum insecticide is cheaper, less harmful and just as effective as those chemical poisons to kill spiders.
  Geoff reckons to use a contact spray like pyrethrum which breaks down within about 24 hours.
  You can purchase concentrated pyrethrum from a nursery or the garden supply section of your supermarket.

Origin

Middle English (denoting pellitory): from Latin, from Greek purethron ‘feverfew’. The current senses (based on the former genus name) date from the late 19th century.

单词	pyrethrum
释义	Definition of pyrethrum in English: pyrethrum noun pʌɪˈriːθrəm 1An aromatic plant of the daisy family, typically having feathery foliage and brightly coloured flowers. 除虫菊 Genus Tanacetum (formerly Chrysanthemum or Pyrethrum), family Compositae: several species, in particular T. coccineum, grown as an ornamental, and T. cinerariifolium, grown as a source of the insecticide pyrethrum Example sentencesExamples This is the area where significant cash crops are grown, including pyrethrum (a flower that produces a natural insecticide), coffee and tea. When I looked closely I could see the truck had a PyGanic label with the iconic pyrethrum flower on the side. Others are synthetic versions of naturally-occurring insecticides, such as those found in the plant pyrethrum. In some areas, extremely fertile soils produce coffee, tea, and pyrethrum (used in making insecticides). Not all herbs smell good - catmint, curry plant, pyrethrum, rue, santolina and tansy are all pretty pongy. Some are derived from plants, such as pyrethrum and neem. 1.1mass noun An insecticide made from the dried flowers of pyrethrum plants. 除虫菊杀虫剂 Example sentencesExamples Pesticides that are approved for organic farming include copper, sulfur, petroleum distillates, and pyrethrum. By the mid 1800s, the heads of chrysanthemum flowers were used to obtain pyrethrum, and rotenone was extracted from the derris plant. ‘That's pyrethrum,’ said Niko ‘it's used as an insecticide.’ Daisy plants were first used centuries ago as a lice remedy in the Middle East, and this led to the discovery of pyrethrum insecticides. You can purchase concentrated pyrethrum from a nursery or the garden supply section of your supermarket. You can treat them with pyrethrum, white oil, soapy water or just squash them with your fingers. A natural pyrethrum insecticide is cheaper, less harmful and just as effective as those chemical poisons to kill spiders. Rotenone and pyrethrum don't work, even if applied more frequently. It seems probable that in the future, synthetic pyrethroids will be of more interest than pyrethrum as possible delousing agents. Adult mosquitoes were obtained from houses within a village by resting and pyrethrum knockdown collections. For body lice, use pyrethrum with piperonyl butoxide lotion over the whole body and wash off after 10 minutes. The spray does not control the adults, so you can either handpick the adults or spray them with pyrethrum insecticide. Geoff reckons to use a contact spray like pyrethrum which breaks down within about 24 hours. Origin Middle English (denoting pellitory): from Latin, from Greek purethron 'feverfew'. The current senses (based on the former genus name) date from the late 19th century. Definition of pyrethrum in US English: pyrethrum noun 1An aromatic plant of the daisy family, typically having feathery foliage and brightly colored flowers. 除虫菊 Genus Tanacetum (formerly Chrysanthemum or Pyrethrum), family Compositae: several species, in particular T. coccineum, grown as an ornamental, and T. cinerariifolium, grown as a source of the insecticide pyrethrum Example sentencesExamples Some are derived from plants, such as pyrethrum and neem. When I looked closely I could see the truck had a PyGanic label with the iconic pyrethrum flower on the side. Others are synthetic versions of naturally-occurring insecticides, such as those found in the plant pyrethrum. This is the area where significant cash crops are grown, including pyrethrum (a flower that produces a natural insecticide), coffee and tea. Not all herbs smell good - catmint, curry plant, pyrethrum, rue, santolina and tansy are all pretty pongy. In some areas, extremely fertile soils produce coffee, tea, and pyrethrum (used in making insecticides). 1.1 An insecticide made from the dried flowers of the pyrethrum plant. 除虫菊杀虫剂 Example sentencesExamples The spray does not control the adults, so you can either handpick the adults or spray them with pyrethrum insecticide. Daisy plants were first used centuries ago as a lice remedy in the Middle East, and this led to the discovery of pyrethrum insecticides. Pesticides that are approved for organic farming include copper, sulfur, petroleum distillates, and pyrethrum. Adult mosquitoes were obtained from houses within a village by resting and pyrethrum knockdown collections. It seems probable that in the future, synthetic pyrethroids will be of more interest than pyrethrum as possible delousing agents. By the mid 1800s, the heads of chrysanthemum flowers were used to obtain pyrethrum, and rotenone was extracted from the derris plant. ‘That's pyrethrum,’ said Niko ‘it's used as an insecticide.’ You can treat them with pyrethrum, white oil, soapy water or just squash them with your fingers. For body lice, use pyrethrum with piperonyl butoxide lotion over the whole body and wash off after 10 minutes. Rotenone and pyrethrum don't work, even if applied more frequently. A natural pyrethrum insecticide is cheaper, less harmful and just as effective as those chemical poisons to kill spiders. Geoff reckons to use a contact spray like pyrethrum which breaks down within about 24 hours. You can purchase concentrated pyrethrum from a nursery or the garden supply section of your supermarket. Origin Middle English (denoting pellitory): from Latin, from Greek purethron ‘feverfew’. The current senses (based on the former genus name) date from the late 19th century.
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