triennial

[trahy-en-ee-uh l]

See more synonyms for triennial on Thesaurus.com

adjective

occurring every three years.
lasting three years.

noun

a third anniversary.
something that appears or occurs every three years.
a period of three years; triennium.

Origin of triennial

First recorded in 1555–65; trienni(um) + -al¹

Related formstri·en·ni·al·ly, adverb

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for triennial

triennial, tertiary, tertian

Examples from the Web for triennial

Contemporary Examples of triennial

For years, the triennial confab has been remarkable mostly for airy oratory by national leaders playing to the crowd back home.
Summit of the Americas in Cartagena Will Be a Minefield for Obama
Mac Margolis
April 13, 2012
Lupton, Cara McCarty, Matilda McQuaid, and Cynthia Smith curated the Triennial.
The Curator's Tale
Ellen Lupton
July 7, 2010

Historical Examples of triennial

The number of graduates, as appears from the triennial catalogue, is 3,191.
The New England Magazine, Volume 1, No. 1, January 1886
Various
We turn again to the Triennial, and count the starred names.
The Education of American Girls
Anna Callender Brackett
Read his report made to the stockholders at their triennial meeting in 1822.
Thirty Years' View (Vol. I of 2)
Thomas Hart Benton
They did so, and found nothing hut a Harvard Triennial Catalogue.
The Luck of Roaring Camp and Other Tales
Bret Harte
The former was in favor of septennial, the latter of triennial parliaments.
Junius Unmasked
Joel Moody

British Dictionary definitions for triennial

triennial

adjective

relating to, lasting for, or occurring every three years

noun

a third anniversary
a triennial period, thing, or occurrence

Derived Formstriennially, adverb

Word Origin for triennial

C17: from Latin triennium

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for triennial

adj.

1630s, "lasting three years;" 1640s, "occurring every three years," from Latin triennium "three-year period," from tri- "three" (see tri-) + annus "year" (see annual). For vowel change, see biennial.