defoliant

noun

de·​fo·​li·​ant (ˌ)dē-ˈfō-lē-ənt 

: 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

Agent Orange is a powerful chemical that kills weeds and acts as a defoliant, which the military used during the war in Vietnam to clear dense jungle and destroy food crops. — Armando Tinoco, Deadline, 10 Aug. 2026

This protection also covers exposures to chromium, chemical defoliants, Agent Orange, and asbestos. — K.h. Koehler, Ascend Agency, 8 May 2026

It was used as a defoliant in Vietnam. — Angus Chen, STAT, 27 Mar. 2026

It was believed this was a result of exposure to Agent Orange, the chemical defoliant used in the Vietnamese jungles. — Chicago Tribune, 26 May 2025

Word History

First Known Use

1943, in the meaning defined above

Kids Definition

defoliant

noun

de·​fo·​li·​ant (ˈ)dē-ˈfō-lē-ənt 

: a chemical that is applied to plants and causes their leaves to drop off