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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

Parkinson’s disease, an inner ear disorder and other neurological problems, all likely caused by the Vietnam vet’s exposure to the infamous defoliant Agent Orange, made it difficult for him to move.

From Seattle Times • Jun. 10, 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

I mentally fist pump and suit up to start on the defoliant.

From "The Last Cuentista" by Donna Barba Higuera

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.