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1.
1. Something cool, roughly equal or greater to 10 mega-fonzies
2. a legend
1. He's so o'malley- he's uber kool!
2. What an o'malley!
by The one and only anonymouse February 09, 2009
 
2.
Only the COOLEST last name ever!
Person 1:You're so lucky your last name is O'Malley.
Person 2:Uh thanks.
Person 1:Yeah mine sucks.
Person 2:Haha sucks for you.
by shanno34 April 25, 2008
 
3.
An Irishman also known as O'Callihan, O'Crowley, O'Toulihan, O'Dowd, O'Houlihan, O'Hanrahan and most notably O'Hara. There are also many other variations. He owns a pub called O'Finnegans and packs massive chomps. A legend in all respects, one that will live on in Irish folklore for many generations to come. He believes in reincarnation and will be reborn as a banana slug in the next life. His brainchild is the NCBA college baseball club team, UCSC slugs in collaboration with the King. The number 7 will be forever retired for all Irish baseball players.
"Nice pitch O'malley, or should i say O'Hanrahan, let me get that chompler."
by O'Grinnelahan February 15, 2010
 
4.
The name of the alter-ego aggressive AI that inhabited the bodies of Tex, Caboose, and now Doc.
"I told you, my name's not Caboose... my name's... O'malley..."
by Speaker for the Dead June 01, 2004
 
5.
Used to describe:
a) a idiot who feels they are significantly smarter than they are
b) a macfag
c) all the above

Can be used as a generic insult as well.
See that kid with his brand new macbook? Such an OMalley.

Person 1: Hey! I just got a 98% on that last test! Suckers!
Person 2: You're such an OMalley
by 1335Ninja July 25, 2010
 
6.
A person who gets obliterated and confrontational after 3-4 drinks. This person is an annoyance to everybody who goes out with him.
Sean was so O'Malleyed the other night he was telling everyone to go fuck themselves after just 3 Coors Light...what a fucking pussy. He must be from Bayonne, New Jersey!
by Curly Red July 10, 2008
 
7.
a asshole...
a asshole tech teacher...
that sucks dick for a living...
the guy is such a o'malley!
by fdjgbdf May 22, 2008