in·​sec·​ti·​cide | \ in-ˈsek-tə-ˌsīd How to pronounce insecticide (audio) \
plural insecticides

Definition of insecticide

: an agent that destroys one or more species of insects broadly : an agent that destroys insects as well as other small pests (such as mites or nematodes) Aphids, mealybugs, and cyclamen mites are all common problems and can be controlled with any low-toxicity insecticide sold specifically for houseplants. Horticulture

Examples of insecticide in a Sentence

Recent Examples on the Web The main ingredient in all PetArmor products is Fipronil, which is an insecticide designed to kill fleas and ticks that are already present. Andrea Marie,, 19 May 2021 An effective natural control is to use a spinosad-containing insecticide found in the Bonide, Fertilome and Southern Ag product lines at independent garden centers when insect damage is first noticed. Tom Maccubbin,, 13 Mar. 2021 But rather than resort to nuking the aphids with some nasty insecticide, Jacob simply cuts back the milkweed plants. Paul Cappiello, The Courier-Journal, 10 July 2021 Within seven days, residents or officials must take countermeasures to prevent mosquitoes from spreading, like spraying walls with insecticide, per the Economist. Theresa Machemer, Smithsonian Magazine, 1 July 2021 Collect and discard caterpillars from plants where the numbers are limited rather than spray an insecticide. Calvin Finch, San Antonio Express-News, 4 June 2021 The systemic insecticide Imidacloprid might have helped earlier. Neil Sperry, San Antonio Express-News, 25 June 2021 These wool-synthetic blend hiking socks are coated with Permethrin, an insecticide (not a repellent) that kills bugs on contact to keep them from hitching a ride on your feet and legs. Matt Jancer, Wired, 22 June 2021 Organophosphates, which account for more than 30% of global insecticide sales, are particularly damaging to bees' neurological functions, even at a lower dose. Karen Kwon | Inside Science, ABC News, 20 June 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'insecticide.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of insecticide

1865, in the meaning defined above

History and Etymology for insecticide

International Scientific Vocabulary

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Time Traveler for insecticide

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The first known use of insecticide was in 1865

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Statistics for insecticide

Last Updated

23 Jul 2021

Cite this Entry

“Insecticide.” Dictionary, Merriam-Webster, Accessed 28 Jul. 2021.

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More Definitions for insecticide



English Language Learners Definition of insecticide

: a chemical substance that is used to kill insects


in·​sec·​ti·​cide | \ in-ˈsek-tə-ˌsīd How to pronounce insecticide (audio) \

Kids Definition of insecticide

: a chemical used to kill insects


in·​sec·​ti·​cide | \ in-ˈsek-tə-ˌsīd How to pronounce insecticide (audio) \

Medical Definition of insecticide

: an agent that destroys insects

Other Words from insecticide

insecticidal \ (ˌ)in-​ˌsek-​tə-​ˈsīd-​ᵊl How to pronounce insecticide (audio) \ adjective


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