triennial [trahy-en-ee-uh l] ExamplesWord Origin 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. 2019 Examples from the Web for triennially Historical Examples of triennially
The visits were repeated biennially till 1890, and then triennially.
Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 6
Various
Some unions meet annually, some biennially, some triennially, and a few determine by referendum when the convention is to meet.
Samuel P. Orth
British Dictionary definitions for triennially triennial adjective
- relating to, lasting for, or occurring every three years
noun
- a third anniversary
- a triennial period, thing, or occurrence
Derived Formstriennially, adverbWord 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 triennially 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.
Online Etymology Dictionary, © 2010 Douglas Harper