Herbicide – A chemical substance used to kill unwanted plants. In the spraying campaign, U.S. and Vietnamese forces intended to kill the targeted vegetation, not merely to remove its leaves.
Dioxin – A persistent and extremely toxic organic pollutant (2,3,7,8 tetrachloro-p-dibenzo-dioxin, or TCDD). The most toxic of all dioxins and dioxin-like compounds, TCDD contaminated Agent Orange, Pink, Purple and Green when the production of one of their components (2,4,5-T) was accelerated during the Vietnam War.
Agent Orange – One of a group of color-coded herbicides that U.S. forces sprayed over rural southern Vietnam from 1961-1971, during the war in Vietnam. A 50/50 mixture of two individual herbicides, 2,4-D and 2,4,5-T, it was used to destroy ground cover and crops used by opposition forces. Other herbicides used included Agents White, Pink, Blue, Purple and Green.