Also found in: Medical, Encyclopedia, Wikipedia.
Related to pyrethrin: permethrin


 (pī-rē′thrĭn, -rĕth′rĭn)
Either of two viscous liquid esters, C21H28O3 or C22H28O5, that are extracted from pyrethrum flowers and used as insecticides.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


1. (Elements & Compounds) Also called: pyrethrin I an oily water-insoluble compound used as an insecticide. Formula: C21H28O3
2. (Elements & Compounds) Also called: pyrethrin II a compound of similar chemical structure and action, also found in pyrethrum. Formula: C22H28O5
[C19: from pyrethrum + -in]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(paɪˈri θrɪn, -ˈrɛθ rɪn)

either of two chemicals, C21H28O3 or C22H28O5, extracted from pyrethrum flowers: used as an insecticide.
[1830–40; pyrethr (um) + -in1]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


n piretrina
English-Spanish/Spanish-English Medical Dictionary Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
Mentioned in ?
References in periodicals archive ?
When hosing off the foliage with a strong jet of water from the hose in midday isn't enough to keep these pests at bay, I spray the leaves with a product that contains pyrethrin and oil, such as Safer Yard and Garden Insect Killer or Pyola.
It's a synthetic version of pyrethrin, which comes from the chrysanthemum.
The price of pyrethrin extract nearly doubled to Sh25,000 over the same period.
In addition, Kenya has the best ecological conditions for the growing of pyrethrum with the highest pyrethrin content and insecticidal compounds.
Places where the bugs take shelter can be sprayed with pyrethrin sprays that have been found effective in eliminating infestations around homes and outbuildings.
Perhaps your most effective natural option is pyrethrin, an insecticide that's produced from chrysanthemums.
thuringiensis; Pyrethrin, Aurobasidium pullulans, and spinosad.
Approximately 93% of cases involved exposure to the TRF active ingredients pyrethroid (78%) or pyrethrin (24%).
These results are consistent with the previous study, which reported that the removal rate of pyrethrin increased by an increase of pH to 8 [25].
Beckman et al., "Characteristics and magnitude of acute pesticide-related illnesses and injuries associated with pyrethrin and pyrethroid exposures-11 states, 2000-2008," American Journal of Industrial Medicine, vol.
Our last tip is to treat doors and windows with pyrethrin spray which is an insecticide that you can buy that will keep the little ones away.