DDT (d??d?-t??)n. A contact insecticide, C14H9Cl5, occurring as colorless crystals or a whitish powder, toxic to humans and animals when swallowed or absorbed through the skin. Most uses have been banned in the United States since 1972.[d(ichloro)d(iphenyl)t(richloroethane).]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.DDT n (Elements & Compounds) dichlorodiphenyltrichloroethane; a colourless odourless substance used as an insecticide. It is toxic to animals and is known to accumulate in the tissues. It is now banned in the UK Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014DDT a toxic compound, C14H9Cl5, formerly widely used as an insecticide. [d(ichloro)d(iphenyl)t(richloroethane)] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.DDT (d??d?-t??) Short for dichlorodiphenyltrichloroethane. A powerful insecticide that is also poisonous to humans and animals. It remains active in the environment for many years and has been banned in the United States for most uses since 1972.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.DDTDichloro-diphenol-trichloroethane. A pesticide with dangerous bioconcentration effects that is banned in much of the West, but still used in developing countries.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited