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defoliant

American  
[dee-foh-lee-uhnt] / diˈfoʊ li ənt /

noun

  1. a preparation for defoliating plants.

defoliant British  
/ diːˈfəʊlɪənt /

noun

  1. a chemical sprayed or dusted onto trees to cause their leaves to fall, esp to remove cover from an enemy in warfare

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of defoliant

First recorded in 1940–45; defoli(ate) + -ant

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

More than half of that spraying involved the dioxin-contaminated defoliant Agent Orange.

From Salon • Apr. 30, 2025

Some deforestation can be traced back to the Vietnam War, when forests were sprayed with the toxic defoliant known as Agent Orange.

From National Geographic • Dec. 20, 2023

He returned regularly to Vietnam after the war to shoot assignments, run photo workshops and photograph victims of Agent Orange, a carcinogenic defoliant sprayed by the American military to clear jungles there.

From New York Times • Aug. 24, 2022

Army, fought in Vietnam and dealt for years with post-traumatic stress disorder and the effects of exposure to the defoliant Agent Orange, he said.

From Seattle Times • Apr. 27, 2022

Ellsberg knew the cause—American planes buzzed 150 feet above the treetops, spraying a defoliant known as Agent Orange.

From "Most Dangerous: Daniel Ellsberg and the Secret History of the Vietnam War" by Steve Sheinkin

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.