a guy who thinks he's better then everyone. when he's drunk he tries to hide it and show off that alcohol doesn't affect him, and then end up throwing up on the bar.
john : dude there are 12 people wanna fight me outside the bar!
matt : ok lets go kick some asses!.
john : wtf man we're only 2 !?
matt : it's ok i got it!!
john : dude stop acting like a frat guy! lets just wait for jack and the others to come over so we can fight back!!

"matt refused to wait and he ended up in hospital,"
by T-Jay October 2, 2013
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A guy who belongs to a fraternity. He does this to drink and hook up with girls. But in reality he joined to hide his homosexuality that will eventually be shown to everyone by senior year when he is caught sucking off some random guy.
Wow bill was the king of the frat back at state. He drank so much. It's so great that he came out and married Michael. Typical frat guy.
by Blumpies Are Awesome September 28, 2020
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Usually in reference to someone who looks like a frat boy, but doesn't act like one. Based purely on the physical aspects, these guys have the frat boy physique, which means a guy dressed well (albeit perhaps a bit abercrombie, a nice mix between prep and hippie) who is tall, athletic, muscular, hunky, and just typically a "guy" in all the right ways. Usually only used by women who happened to be attracted to such guys.
He's so hot, he's got the "frat guy" style going and it looks good on him!

I'm diggin' the frat guy at the bar...
by Charley D. October 7, 2008
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