Al·thing (äl?th?ng, ôl?-)n. The parliament of Iceland. It is the oldest assembly in Europe, first convened in 930.[Old Norse althing, parliament, whole assembly : allr, all; see al- in Indo-European roots + thing, assembly.]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.Althing (?æl???) n (Government, Politics & Diplomacy) the bicameral parliament of IcelandCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Althing a whole assembly, specifically, the General Assembly of Iceland.Dictionary of Collective Nouns and Group Terms. Copyright 2008 The Gale Group, Inc. All rights reserved.