Source : WordNet®

solemnise
     v 1: observe or perform with dignity or gravity; "The King
          solemnized this day of morning" [syn: {solemnize}]
     2: perform (the wedding ceremony) with proper ceremonies [syn:
        {solemnize}]
     3: make solemn and grave; "This ceremony solemnized our hearts"
        [syn: {solemnize}]