quincentenary
nounA 500th anniversary or celebration.
adjectiveOf or relating to a span of 500 years or to a 500th anniversary.
Relating to or consisting of five hundred, especially five hundred years.
nounThat which consists of or comprehends five hundred.
nounA five-hundredth anniversary.
nounA
Pertaining to a quincentenary;
the 500th anniversary (or the celebration of it)
adjectiveof or relating to a 500th anniversary