an animated show about a giant megadeus (mech), the Big O, and it's Dominus (pilot), Roger Smith.
The Big O airs at 1:30 am on Adult Swim
by Paradigm City March 18, 2005
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The face of suprise somebody makes when you abruptly shove something into their anus.
When I shoved my penis into her ass, she did a Big O.
by SigiaZ August 23, 2011
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The semi-official, fresh-from-marketing nickname for Omaha, Nebraska. Latest in a number of slogans designed to give Omaha an "image", this one seems to have stuck, the fact that it has not enhanced Omaha's image one jot notwithstanding. Most commonly used in "buy the big O"; i.e., keep your dollars in the local economy.
Remember to support your local retailers and buy the big O!
by regular_gonzalez October 28, 2005
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Montreal slang for the Olympic Stadium, where the Expos baseball team and Allouettes football teams have played at various times. Also home to a large and extremely well done natural history museum. Now vacant, except for large expositions such as the Home Show. Charactorized on the Montreal skyline by the slanted concrete tower with a finicular railway running up to the top. aka: The Big Toilet Built for the 1976 Summer Olympics, but the tower was not finished until some time in the late 80's Meant to be the first stadium with a fully retractable roof, it was not fully functional until the early 90's, but the parachute and cable design proved too unreliable.
U2 will be performing at the Big O this evening.

We should've demolished the Big Toilet years ago, before it became the white elephant it is today. We're still paying for it, all these years later!
by G.H. Hadden May 3, 2005
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The awesomest man to walk the earth(Oliver), this term has become his title, and legend, after bringing pleasure to many women.
Who fucked her? Big O nailed that biatch!
by AllofHer March 20, 2004
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