1. Happening once every 20 years.
2. Existing or lasting for 20 years.

[From Late Latin vīcennium, period of twenty years : Latin vīciēns, twenty times (from vīgintī, twenty; see vicenary) + Latin annus, year; see at- in Indo-European roots.]
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.


1. occurring every 20 years
2. relating to or lasting for a period of 20 years
[C18: from Late Latin vīcennium period of twenty years, from Latin vīciēs twenty times + -ennium, from annus year]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(vaɪˈsɛn i əl)

1. of or for twenty years.
2. occurring every twenty years.
[1730–40; < Latin]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.vicennial - occurring once every 20 years
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
As our state embarks on its third vicennial Constitution Revision Commission (CRC), University of Florida Law Professor Mary Adkins' new book Making Modern Florida could not be timelier.
In 2003 he received the Department of Defense Medal for Distinguished Public Service; in 2005, the Vicennial Medal for his many years of graduate teaching at Georgetown University; and in 2013, the Chief Scientist's Medal for Excellence, Global Strike Command.
A QUEST for timeless beauty, talent and wit will be showcased at the July Rose beauty pageant, as it celebrates its vicennial anniversary this year.
However, the simulations as a whole show that a significant population response occurs at its most rapid rate on decadal to vicennial timescales, with a half century being the more likely time span.
Another vicennial anniversary gift from Tige came in the form of Platinum Editions of the RZ2, RZ4 and all-new RZR 20-footer.