occurring every eight years.
of or for eight years.
Origin of octennial
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for octennial
Historical Examples of octennial
Octennial, ok-ten′i-al, adj. happening every eighth year: lasting eight years.
Of late these shackles, if I mistake not, have been broken; and octennial parliaments have besides been established.The Federalist Papers
Alexander Hamilton, John Jay, and James Madison
occurring every eight years
lasting for eight years
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