duodecennial

Related to duodecennial: Epicedial, Detrite, heteromorphy, subscriptive

duodecennial

(ˌdjuːəʊdɪˈsɛnɪəl)
adj
relating to twelve years
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

Duodecade, Duodecennial

 a period of twelve years, 1656.
Dictionary of Collective Nouns and Group Terms. Copyright 2008 The Gale Group, Inc. All rights reserved.