1) Used to describe one's genitals.
2) Used in place of the name of any STD or multiple STDs. In order to convey this meaning accurately, one must hold both hands out and wiggle all 10 fingers independently while saying the word "duuudes".
3) Used to replace just about any noun in the English dictionary, similar to the way we use the word "stuff".
a) "She kicked me in the duuudes".
b) "I got her to suck on my duuudes"
a) "Be careful with her. I hear she's got duuuded".
B) "Oh man, this sucks! That hooker gave me duuudes!"
a) "Hey honey, don't forget your duuudes that you left on the table"!
b) "I've gotta stop by the bank and withdraw some duuudes".
c) I'm hungry. I've gotta stop at McDonald's and get me some duuudes".