Dude, you've got to read this...
CNN article on dude. Extract below:
"A linguist from the University of Pittsburgh has published a scholarly paper deconstructing and deciphering the word "dude," contending it is much more than a catchall for lazy, inarticulate surfers, skaters, slackers and teenagers.
An admitted dude-user during his college years, Scott Kiesling said the four-letter word has many uses: in greetings ("What's up, dude?"); as an exclamation ("Whoa, Dude!"); commiseration ("Dude, I'm so sorry."); to one-up someone ("That's so lame, dude."); as well as agreement, surprise and disgust ("Dude.").
Kiesling says... that the word derives its power from something he calls cool solidarity -- an effortless kinship that's not too intimate. Cool solidarity is especially important to young men who are under social pressure to be close with other young men.....In other words: Close, dude, but not that close. "It's like man or buddy, there is often this male-male addressed term that says, 'I'm your friend but not much more than your friend,"' said Kiesling, whose research focuses on language and masculinity...
Historically, dude originally meant "old rags" -- a "dudesman" was a scarecrow. In the late 1800s, a "dude" was akin to a "dandy," a meticulously dressed man, especially out West. It became "cool" in the 1930s and 1940s, according to Kiesling. Dude began its rise in the teenage lexicon with the 1981 movie "Fast Times at Ridgemont High."
"Dude" also shows no signs of disappearing as more and more of our culture becomes youth-centered, said Mary Bucholtz, an associate professor of linguistics at the University of California, Santa Barbara...."