decennium [-ē əm]
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
noun pl. decenniums or decennia
decade (sense )
Origin: Classical Latin ; from decennis: see decennary
Used by arrangement with John Wiley & Sons, Inc.
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
noun pl. de·cen·ni·ums
A period of ten years; a decade.
Origin: Latin, from decennis, lasting for ten years : decem, ten; see dekm̥ in Indo-European roots + annus, year; see at- in Indo-European roots.