The Collaborative International Dictionary of English v.0.48:
Adventism \Adventism\ n. 1. 1 any Christian religion that believes the second coming of Christ is imminent. Syn: Second Adventism [WordNet 1.5]WordNet (r) 3.0 (2006):
Adventism n 1: any Christian religion that believes the second coming of Christ is imminent [syn: Adventism, Second Adventism]