in World of Warcaft, a funny way for Horde players to annoy scare Alliance players.
Because of the language mess-up system in WoW, if a Horde player says "UO UO", any Alliance player who hears it will see "HA HA" instead. most of Allys run away seeing that, thinking they've met a GM's alt who has cross-faction communication. "UO UO" can be extended, so if you prefer "HA HA HA" over "HA HA", there's no problem!

try it out!
Horde player: *kills an alliance player* UO UO

Other alliance player to alliance player: omg this guy can write to us normally O.o i better run away hes a gm or something cya *bubble hearth*
by vtf_sandvich March 7, 2009
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When a person mistypes “up” on a phone.
Guy 1 on phone: Have you watched Uo recently?
Guy 2 on phone: did you say Up?
Guy 2: SHIT
by ion0320 November 2, 2018
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Unpopular Opinion. When you express an opinion that is completely against what most people say.
by BlaineW October 1, 2011
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Short for Ultima Online, a game released in late 1997. This was the "first" successful MMORPG (Yes technically there were others but none on the scale of UO). It was possibly one of the most unique and immersive games in the market at its peak (98-01). The game was quickly massacred and mutilated beyond recognition with nerfs/cheesy neon graphics after the release of its third expansion.
I used to play UO for the PvP... now I'm waiting for WoW
by Azaroth March 26, 2004
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The University of Oregon, located in Eugene, OR. Often confused with OU (University of Oklahoma), another high caliber university. UO has a solid reputation as one of the top flagship universities on the West Coast. A member of the AAU (Association of American Universities) that consists of 62 best public and private universities in terms of research and education. UO's athletic teams, the Ducks, compete in the Pacific 10 conference.
UO is a fine university that combines excellent academics with an elite athletic program.
by Michael.Bennett September 11, 2007
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Short for Ultima Online. It is overall a very interesting game that has been around for five, nearing six, years. In essence, it is a drug.
"Sorry Honey, can't come to bed yet, I'm busy playing UO."
by Lonegamer May 23, 2003
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UO is a PC game, short for Ultima Online. It first came about around the end of September to early October of 1997, and is still running today. It was originally 2D, but now had spread to 3D, and has around 250,000 players from all over the world. The setting is, in my opinion, semi-Renaissance, with mages and magical spells, dragons, "recalling", which is casting a spell to get from one place to another, house ownership, items, weapons, monsters, and unlimited possibilities. You can talk to people, form hunting parties, even guilds and communities. Unfortunately, the game has been a bit nerfed for years, and ever since Age of Shadows, an expansion pack, the game isn't what it used to be. But the game is always changing, and can still be great fun.
Aww, they ran out of UO gametime cards...
by Angelfyre April 4, 2005
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