|a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
dioxin di·ox·in (dī-ŏk'sĭn)
Any of several carcinogenic or teratogenic heterocyclic hydrocarbons that occur as impurities in petroleum-derived herbicides.
|dioxin (dī-ŏk'sĭn) Pronunciation Key
Any of several toxic hydrocarbons that occur as impurities in petroleum-derived herbicides, disinfectants, and other products. Dioxins are composed of two benzene rings connected by two oxygen atoms, and the most familiar kind, called TCDD, has two chlorine atoms attached to each benzene ring. TCDD was once thought to cause cancer and birth defects, but subsequent research showed it to have only mild toxic effects except at very high exposure levels.
A group of pollutants created as by-products in many industrial processes. Dioxins accumulate in human tissue and affect human metabolism. They are carcinogens. Eliminating dioxins is an important goal of environmental policy.