Definition of quincentennial in US English:

quincentennial

noun

  • The five-hundredth anniversary of a significant event.

    • ‘In the year 1992, the quincentennial of the arrival of Columbus in this hemisphere, there were meetings all over the country to celebrate him, but also, for the first time, to challenge the customary exaltation of the Great Discoverer.’
    • ‘Portugal is all too keen to exploit the quincentennial for a glorious reassertion of its place within the European Community which has kept it at the margins for centuries.’

adjective

  • Relating to a five-hundredth anniversary.

Origin

Late 19th century: from Latin quinque ‘five’ + centennial.

Pronunciation

quincentennial

/ˌkwinsenˈtenēəl/