Nouns

(n)ceremony, ceremonial, ceremonial occasion, observancea formal event performed on a special occasion“a ceremony commemorating Pearl Harbor”
(n)ceremonyany activity that is performed in an especially solemn elaborate or formal way“the ceremony of smelling the cork and tasting the wine”, “he makes a ceremony of addressing his golf ball”, “he disposed of it without ceremony”
(n)ceremonythe proper or conventional behavior on some solemn occasion“an inaugural ceremony”