py·rol·y·sis (p?-r?l??-s?s)n. Decomposition or transformation of a compound caused by heat.py?ro·lyt?ic (-r?-l?t??k) adj.py?ro·lyt?i·cal·ly adv.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.pyrolysis (pa??r?l?s?s) n1. (Chemistry) the application of heat to chemical compounds in order to cause decomposition2. (Chemistry) chemical decomposition of compounds caused by high temperatures pyrolytic adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014py?rol?y?sis (pa??r?l ? s?s) n. 1. the subjection of organic compounds to very high temperatures. 2. the resulting decomposition. [1885?90] py`ro?lyt?ic (-r??l?t ?k) adj. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.pyrolysisthe chemical process of decomposition under the effect of heat. ? pyrolitic, adj.See also: Heat-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.pyrolysisThe decomposition of a substance by heat.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited