de·​fo·​li·​ant | \ (ˌ)dē-ˈfō-lē-ənt How to pronounce defoliant (audio) \

Definition of defoliant

: a chemical spray or dust applied to plants in order to cause the leaves to drop off prematurely

Examples of defoliant in a Sentence

Recent Examples on the Web The Vietnam War brought the helicopter gunship, napalm, and chemical defoliants. David Oshinsky, The New York Review of Books, "‘The Human Mind Was Not Made for War’," 28 Jan. 2020 That represented an upgrade from a previous recommendation that there was inadequate or insufficient evidence to link the diseases to the toxic herbicides used as defoliants in Vietnam. Fox News, "Veterans face more delays on Agent Orange relief," 26 Oct. 2019 The most infamous of these facilities produced nearly a million gallons of Agent Orange, the toxic defoliant whose extensive use during the Vietnam War has caused generations of suffering. Wired, "How Cities Reshape the Evolutionary Path of Urban Wildlife," 23 Sep. 2019 Last August, recreational divers discovered barrels labeled as containing one of two defoliants -- 2,4-D or 2,4,5-T. Combined, the two chemicals were once known as Agent Orange. Rob Davis | The Oregonian/oregonlive,, "U.S. EPA finds 18 barrels, some intact, in Wallowa Lake recovery effort," 14 June 2019 After a 10-month wait, preliminary work began Thursday on the delicate task of removing barrels sitting in Wallowa Lake marked as containing defoliants used in Agent Orange. Rob Davis | The Oregonian/oregonlive,, "Recovery begins on Wallowa Lake barrels that may contain Agent Orange ingredients," 13 June 2019 Mattis visited an air base north of Ho Chi Minh City that was heavily contaminated in the late 1960s and early 1970s by American forces through storage and spillage of the chemical defoliant Agent Orange. Robert Burns, The Seattle Times, "US defense secretary sees the enduring costs of Vietnam War," 16 Oct. 2018 Mattis thanked Vietnamese officials for their cooperation in recovering missing troops and recognized the years-long U.S. efforts to clean up toxic sites in the south, where Agent Orange and other defoliants were kept. Alex Horton, Washington Post, "Vietnam War loomed over Mattis’s two days in Hanoi," 26 Jan. 2018 The haphazard method of incineration generated numerous pollutants, including carbon monoxide and dioxin—the same chemical compound found in Agent Orange, the dangerous defoliant during the Vietnam War. Perry Chiaramonte, Fox News, "Former burn pit inspector says warnings were largely ignored by Pentagon officials during Iraq War," 7 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'defoliant.' 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 defoliant

1943, in the meaning defined above

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The first known use of defoliant was in 1943

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Last Updated

4 Feb 2020

Cite this Entry

“Defoliant.” Dictionary, Merriam-Webster, Accessed 16 Feb. 2020.

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How to pronounce defoliant (audio)

English Language Learners Definition of defoliant

technical : a chemical that is sprayed on plants to make their leaves fall off

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Nglish: Translation of defoliant for Spanish Speakers Encyclopedia article about defoliant

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