quincentennial
noun
quin·centen·ni·al ˌkwin-sen-ˈte-nē-əl 
: quincentenary
quincentennial adjective
Did you know?
The United States is such a young country that it will be quite some time before we reach our quincentennial as a nation: 2276 A.D., to be exact. Some American cities will celebrate their quincentennials long before that, but even St. Augustine, Florida, the nation's oldest city, will have to wait until 2065. Meanwhile, many young people can look forward happily to our national tricentennial in 2076; and their grandchildren may be around for our quadricentennial in 2176.
Example Sentences
Recent Examples on the Web As Guam, the Philippines, Spain and even Portugal celebrate and question the quincentennial, the explorer’s legacy remains as complicated as ever. 
Erin Blakemore, National Geographic, 19 Sep. 2019 Then, the painting will return to the Salle des États in time for a landmark exhibition celebrating the quincentennial of da Vinci’s death. Todd Plummer, Condé Nast Traveler, 15 Aug. 2019
Erin Blakemore, National Geographic, 19 Sep. 2019 Then, the painting will return to the Salle des États in time for a landmark exhibition celebrating the quincentennial of da Vinci’s death. Todd Plummer, Condé Nast Traveler, 15 Aug. 2019 Word History
Etymology
Latin quinque five + English centennial
First Known Use
1884, in the meaning defined above