(n) :
of a significant event, a day that is an exact number of years (to the day) since the event occurred; often preceded by an ordinal number indicating the number of years that have elapsed since the event; specifically, a wedding anniversary
"today is the fiftieth anniversary of the end of the war."
(n) :
of a significant event, a day that is an exact number of years (to the day) since the event occurred; often preceded by an ordinal number indicating the number of years that have elapsed since the event; specifically, a wedding anniversary
"today is the fiftieth anniversary of the end of the war."