YTabbr. Yukon TerritoryAmerican 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.yt the internet domain name for (Computer Science) Mayotte Yt the chemical symbol for (Elements & Compounds) (formerly) yttrium. Now: Y YT (esp in postal addresses) abbreviation for (Placename) Yukon TerritoryCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014YT Yukon Territory. Y.T. Yukon Territory. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.YTYou there?Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited