[n] any joyous diversion
[n] the public performance of a sacrament or solemn ceremony with all appropriate ritual; "the celebration of marriage"
[n] a joyful occasion for special festivities to mark some happy event
festivity - (4 syllables), jubilation - (4 syllables), solemnisation - (5 syllables), solemnization - (5 syllables)
affair, blowout, conviviality, diversion, festival, fete, function, gala, gala affair, Isthmian Games, jamboree, jollification, merrymaking, occasion, Olympian Games, Olympic Games, recreation, ritual, social function, social occasion, victory celebration
\Cel`e*bra"tion\, n. [L. celebratio.] The act, process, or time of celebrating. His memory deserving a particular celebration. --Clarendok. Celebration of Mass is equivalent to offering Mass --Cath. Dict. To hasten the celebration of their marriage. --Sir P. Sidney.