WordNet sense 1 (of momentous or ominous significance):

prodigious

WordNet sense 2 (important in effect or meaning):

important, significant

WordNet sense 3 (ominously prophetic):

fateful, foreboding

WordNet sense 4 (foretelling events as if by supernatural intervention):

prophetic, prophetical

WordNet sense 5 (puffed up with vanity):

grandiloquent, overblown, pompous, pontifical

WordNet sense 6 (making claim to or creating an appearance of (often undeserved) importance or distinction):

pretentious