The Collaborative International Dictionary of English v.0.48:
Merrymaker \Mer"ry*mak`er\, n. One who makes merriment or indulges in conviviality; a jovial comrade. [1913 Webster]WordNet (r) 3.0 (2006):
merrymaker n 1: a celebrant who shares in a noisy party; "the clubs attract revelers as young as thirteen" [syn: reveler, reveller, merrymaker]