[dih-sen-ee-uh l]


of or for ten years.
occurring every ten years.


a decennial anniversary.
its celebration.

Origin of decennial

1650–60; < Latin decenni(um) a period of ten years (decenn(is) decennary + -ium -ium) + -al1
Related formsde·cen·ni·al·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for decennial

decimal, decuple, denary, tenfold

Examples from the Web for decennial

Historical Examples of decennial

British Dictionary definitions for decennial



lasting for ten years
occurring every ten years


a tenth anniversary or its celebration
Derived Formsdecennially, adverb
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 decennial

1680s, from Latin decennium, from decennis "of 10 years," from decem "ten" (see ten) + annus "year" (see annual). For vowel change, see biennial.

Online Etymology Dictionary, © 2010 Douglas Harper