[ok-ten-ee-uh l]
See more synonyms for octennial on Thesaurus.com

Origin of octennial

1650–60; < Late Latin octenni(um) eight-year period (oct- oct- + -enn-, combining form of annus year + -ium -ium) + -al1
Related formsoc·ten·ni·al·ly, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for octennial

octagonal, octennial

Examples from the Web for octennial

Historical Examples of octennial

British Dictionary definitions for octennial


  1. occurring every eight years
  2. lasting for eight years
Derived Formsoctennially, adverb

Word Origin for octennial

C17: from Latin octennium eight years, from octo eight + annus year
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