Portentous (caught our attention here): fateful; ominously prophetic; of momentous or ominous significance; grandiloquent; puffed up with vanity; pompous.

Events in history that capture both meanings flawlessly:

• Napoleon, 1769-1821: “Power is my mistress. I have worked too hard at her conquest to allow anyone to take her away from me.”
• George W. Bush, WMDs, 2003
• Paris Hilton, Vote or Die Campaign, 2006
• Ted Haggard, sex scandal, 2006
• John McCain, DADT, 2010

“but wait” you say, “i love this word so much, i wish i had it on a shirt!” good thing the internet rarely disappoints.