cel·e·brant 
(sĕlə-brənt)
(sĕlə-brənt)n.
1.
a. A person who participates in a religious ceremony or rite.
b. A person who officiates at a religious or civil ceremony or rite, especially a wedding.
c. In some Christian churches, the cleric officiating at the celebration of the Eucharist.
2. A participant in a celebration.
Usage Note: Celebrant originally referred to an official participant in a religious ceremony or rite. In the United States, celebrant developed an extended meaning: "a participant in a celebration," as in The New Year's Eve celebrants went wild at the stroke of midnight. As far back as 1965, half of the Usage Panel accepted this extended sense, and over the years, the margin of approval by the Panel has increased. By 2006, 80 percent of the Panel accepted this usage.