triennium(redirected from trienniums)
n. pl. tri·en·ni·ums or tri·en·ni·a (-ĕn′ē-ə)
A period of three years.
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.
n, pl -niums or -nia (-nɪə)
a period or cycle of three years
[C19: from Latin, from tri- + annus a year]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
tri•en•ni•um(traɪˈɛn i əm)
n., pl. -en•ni•ums, -en•ni•a (-ˈɛn i ə)
a period of three years.
[1840–50; < Latin, =trienn(is) pertaining to three years (tri- tri- + -ennis, adj. comb. form of annus year) + -ium -ium1]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
Trienniuma period of three years, 1847.
Dictionary of Collective Nouns and Group Terms. Copyright 2008 The Gale Group, Inc. All rights reserved.