tox·ic·i·ty (t?k-s?s??-t?)n. pl. tox·ic·i·ties 1. The quality or condition of being toxic.2. The degree to which a substance is toxic.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.toxicity (t?k?s?s?t?) n1. the degree of strength of a poison2. the state or quality of being poisonousCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014tox?ic?i?ty (t?k?s?s ? ti) n., pl. -ties. the quality, relative degree, or specific degree of being toxic or poisonous. [1880?85] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.