1. A formal act or set of acts performed as prescribed by ritual or custom: a wedding ceremony; the Japanese tea ceremony.

2. A conventional social gesture or act of courtesy: the ceremony of shaking hands when introduced.

3. A formal act without intrinsic purpose; an empty form: ignored the ceremony of asking for comments from other committee members.

4. Strict observance of formalities or etiquette: The head of state was welcomed with full ceremony.