TCDD

1.
Pharmacology. dioxin.
noun, Chemistry.
1.
a general name for a family of chlorinated hydrocarbons, C 12 H 4 Cl 4 O 2 , typically used to refer to one isomer, TCDD, a by-product of pesticide manufacture: a toxic compound that is carcinogenic and teratogenic in certain animals.
noun
1.
any of a number of mostly poisonous chemical by-products of the manufacture of certain herbicides and bactericides, esp the extremely toxic 2,3,7,8-tetrachlorodibenzo-para-dioxin

dioxin di·ox·in (dī-ŏk’sĭn)
n.
Any of several carcinogenic or teratogenic heterocyclic hydrocarbons that occur as impurities in petroleum-derived herbicides.
dioxin
(dī-ŏk’sĭn)
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.
dioxin [(deye-ok-sin)]

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.
TCDD
tetrachlor dibenzo dioxin