-ennium
A period of years.
[Latin annum, year.]
Terms are based on Latin number prefixes (see the entry Number words): biennium, a period of two years; triennium, of three; quadrennium, four; quinquennium, five; decennium, ten; and millennium, a thousand years.
Visit Michael Quinion’s World Wide Words site for 2000+ articles on English!
Copyright © Michael Quinion 2008–. All rights reserved. Page last updated 23 September 2008.
Your comments and suggestions on the site are very welcome.