Agent Orange

WordReference Random House Learner's Dictionary of American English © 2026

ˈA•gent ˈOr•ange, n. [uncountable]

1. Pest Control a powerful herbicide containing small amounts of dioxin, used heavily during the Vietnam War.

WordReference Random House Unabridged Dictionary of American English © 2026

A′gent Or′ange, 

1. Agriculture, Pest Control a powerful herbicide and defoliant containing trace amounts of dioxin, a toxic impurity suspected of causing serious health problems, including cancer and genetic damage, in some persons exposed to it and birth defects in their offspring: used by U.S. armed forces during the Vietnam War to defoliate jungles.

• so called from the color of the identifying stripe on the drums in which it was stored 1965–70

Collins Concise English Dictionary © HarperCollins Publishers::

Agent Orange noun

1. a highly poisonous herbicide used as a spray for defoliation and crop destruction, esp by US forces during the Vietnam War

Etymology: 20th Century: named after the identifying colour stripe on its container