triennial

[ trahy-en-ee-uhl ]
/ traɪˈɛn i əl /

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.

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Origin of triennial

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

OTHER WORDS FROM triennial

tri·en·ni·al·ly, adverb

Words nearby triennial

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for triennial

British Dictionary definitions for triennial

triennial
/ (traɪˈɛnɪəl) /

adjective

relating to, lasting for, or occurring every three years

noun

a third anniversary
a triennial period, thing, or occurrence

Derived forms of triennial

triennially, 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