celebrant (suomeksi)

vihkipappi (s: person who officiates at a religious ceremony / vihkipappi / at marriage)
ehtoollispappi (s: person who officiates at a religious ceremony / vihkipappiehtoollispappi / at Eucharist)
selebrantti (s: person who officiates at a religious ceremony / vihkipappiehtoollispappi / person who conducts formal ceremonies)
juhlija (s: person who is celebrating something)
juhlaväki (s: person who is celebrating something / juhlaväki / collectively)