To have sexual intercourse with a girl in a very non-romantic or passionate way, for the sole purpose of elevating one's manly stature. Usually achieved through the use of excessive allusions and peer pressure, and followed by excessive bragging in deep manly vocal register to one's bros.

Note the phonetic similarity between "to do" and "to dude".
Kathleen - "So last night I had this really weird dream."
Jade - "Did it involve midgets in plaid?"
Kathleen - "It did, actually. One was trying to dude me. He wanted to be able to brag to his friends, but then a dragon flew by and devoured him. And I just sat there wearing a Queen Amidala costume."
Jade - "You had that dream last week."
Kathleen - "Yeah...I think I need therapy."

Example 2:
Bro 1 - I totally did Sarah last night.
Bro 2 - Do you like her?
Bro 1 - Eh, she's okay.
Bro 2 - (thinks to self) Oh, he duded her. I can't decided if that makes him cool or not. I think it does.
by katnjade October 19, 2009
A common expression when someone is witnessing a gross, disgusting, revolting, or generally displeasing or uncomfortable action.

1st Dude: "Not Cool," a warning to the person starting the action
2st Dude: Rising anger, starting to understand what is happening
3rd Dude: Total outrage and bafflement, shock at what is taking place.
Kevin: Hey, I gotta show you something...
*starts unzipping pants*
Brad: What? Dude, DUDE, DUDE!!!
*Kevin pees on Brad*
by Artemis Google October 28, 2006
Somebody who is manly, but also just a dude. A chill person you can laugh and enjoy a summer day with.
Broooo look at him just being a dudes dude.
by Lucky shot May 11, 2019
You're Mr. Lebowski. I'm the Dude, so that's what you call me. Or maybe His Dudeness, or Duder, or El Duderino if you're not into the whole brevity thing.
by Shawn E. November 11, 2003
Jay from the Kubz Scouts.
Person: *goes to a video with Jay in it*

and comments "that dude sent me"
by FifthArrow11 August 13, 2017
n. (Your Dudness or His Dudeness or Her Dudeness) title used to establish one's ultimate position in the "dude" hierarchy, "Dudeness" being the ultimate ruler of all or at least most other dudes.
"Dudeness over there is sendin' you the googly eyes."
"He's sendin' the googlies?"
by manlymanlyman July 26, 2005
Manlove, gay sex, love between two men (typically homosexuals).
"Richard Simmons loves it 'Dude On Dude'."
"Really?"
by Jaburoma August 14, 2006