The person everyone loves to hate and never wants to become.
You're driving and get stuck in the middle of the intersection just as the light turns red. Now, because of you no one can get by. You have now become "That Guy".
by Desiree April 17, 2005
(n.) a hypothetical "guy" who likes to make an ass of himself or does awkward, weird, or unkind things.

This "guy" is usually referred to and compared to when someone is doing something awkward or annoying.
*is making ass of self*
Person: Why do you have to be that guy?
by gamerdude949494949 October 26, 2009
The most annoying person at a social outing or gathering, especially when alcohol is involved.
Whatshisnuts- "Dude, So-and-so was being 'That Guy' at the party last night."
Theotherguy- "Yeah, especially when he kept screaming then telling people to shut up."

by MoStang June 5, 2007
An individual at any given social event who crosses the line of severe Obscenity/Indecency/Profanity typically involving speech or actions, often vulgar and unnecessary. Doing so defines his title of "That guy". See also; jackass, Andrew, Fatkid.
Party Goer "Yes I do indeed enjoy box wine."

That Guy "I go down on my fat ex girlfriend when its her time of the month"

Party Goer" Oh, so you're that guy, please get away from me"

That Guy " Waaaahhhh You think I'm a fat loser and I only like fat chicks."
by Dr. Ovenglover July 11, 2008
That Guy refers to a person who appears in the background of a photograph often without the consent or knowledge of the photogropher of subjects of the picture. That guy often takes the focus of the photo off the intended subject. That guy is often seen making a funny face or rude gesture, commonly a blowjob gesture. There is a category on college humor.com of That Guy pictures.
I took a picture of my friends at the beach but That Guy is right in the middle of it.
by cdizz July 24, 2006
Anonymous co-worker in your organisation. Possibly frozen in time from the 1980s and the toast of Wall Street. He’ll be ready to sleaze his way to the top, 80s style! He knows about business and has a tie. Also went to a lot of coke parties. The secret to his success is all about appearances. Outside of the office he goes back to the farm, shifts some paradigms and revolutionises outside the box. Liked the Safety Dance and died from Boneitis.
“Who shall we pick to be our new CEO?”
“I nominate That Guy!”
by Lugs-o October 18, 2004