Synonyms for Celebration (same or very similar meaning)
WordNet sense 1 (a joyful occasion for special festivities to mark some happy event):
jubilationWordNet sense 2 (the public performance of a sacrament or solemn ceremony with all appropriate ritual):
solemnization, solemnisationWordNet sense 3 (any joyous diversion):
festivityFrom the ODE community, based on WordNetadd/edit