a dude is a guy. that's basically all there is to it. sometimes, you might just use it to address anyone though. it's just a way to acknowledge people.
Dude 1: "Dude, she is hot!"
Dude 2: "Um, dude, no she isn't."
Dude 2: "Um, dude, no she isn't."
by Mandy Ganus June 27, 2006
Get the dudemug. 
To Use "The Dude" on some one - to invoke the word "dude" when
referring to someone directly in an (often last-ditch) effort to relate
to that person on a less formal or "guy to guy" level.
referring to someone directly in an (often last-ditch) effort to relate
to that person on a less formal or "guy to guy" level.
Ex. 1.: "Then, I used the dude on him, but he still didn't get it?"
Ex. 2.: "I used the dude on him. I said, "hey, dude; that's weird."
Ex. 2.: "I used the dude on him. I said, "hey, dude; that's weird."
by Aaron R. Wunderlich, John Raymond September 29, 2003
Get the the dudemug. 
by winwood November 5, 2005
Get the that dudemug. An elephant butt hair.
by Bob's Sausage June 8, 2004
Get the dudemug.