What is Quinquecentenary?

Quinquecentenary definition and meaning on Dictionary terms:
A Norwegian military officer and politician of the twentieth century. He collaborated with the Germans in their conquest of Norway in World War II; the Germans rewarded him by making him leader of the German-controlled government of the country. After the German defeat, the Norwegian government had Quisling tried for treason and executed.


reference: www.dictionary.com/browse/quinquecentenary