centennial

Definitions:

A centenary.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
Pert. to a hundred years.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (adjective) (adj.) (adjective)
Lasting or having lived a hundred years; happening every hundred years.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (adjective) (adj.) (adjective)
Happening once in a hundred years.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (adjective) (adj.) (adjective)
Happening once in a century.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (adjective) (adj.) (adjective)
Consisting of, or enduring, a hundred years; taking place once in a hundred years.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (adjective) (adj.) (adjective)
The celebration of a hundredth anniversary.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)

Usage examples:

That was the Centennial year- '76. This is another eventful year for the cavalry,- '77; for before the close of the summer even the troops so far to the southeast are destined to be summoned to the chase and capture of wary old Chief Joseph,- the greatest Indian general ever reared upon the Pacific slope,- and even now, on this July day, here are cavalrymen at their accustomed task, and though it is five years since we saw them under the heat and glare of the Arizona sun, there are familiar faces among these that greet us.
- Foes in Ambush by Charles King
Immense crowds lined the streets, and all available space in the great Centennial Park was covered with people.
- The Chronicles of a Gay Gordon by José Maria Gordon
He finds them, greatly advanced in civilisation, celebrating what we should call nowadays his centennial and making his name the refrain of their songs.
- Views and Reviews by Henry James