ceremony in WordNet English dictionary

1. a formal event performed on a special occasion
   "a ceremony commemorating Pearl Harbor"
   ceremony  ceremonial  ceremonial occasion  observance 
   
2. the proper or conventional behavior on some solemn occasion
   "an inaugural ceremony"
   ceremony 
   
3. any 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"
   ceremony