Duder is a word of many possibilites. It can be used as a replacement for dude. It can also be used to mean someone is more dude-like than someone else (as in dude, duder, dudest.) It has also been known to be used to describe objects for which the name has been temporarily forgotten, or otherwise unknown to the user of the word. Still yet another usage is a verb which means the act of being a dude or doing dudely things.
Hey duder, come over to my house.
Steve is duder than I am, but surely not the dudest guy in the room.
Beth need help to figure out how to opperate this new duder she got.
I think I'm going to go put on my sunglasses and duder around town.
A hardcore dancer is a person usually in their teens who has immense quantities of angst due to listening to hardcore and emo music.
These teens will go to concerts wearing tight pants, and tight jeans. Instead of the usual mosh pit, they will take play in hardcore dancing. This consists of swining their arms and legs around in a random fashion attempting to look they like are fighting invisiable enemies all around them.
Hardcore dancers are known to look like idiots, but seem to not care.
Chad demanded that everyone in the mosh pit beat up all hardcore dancers.