The word was introduced in the entertainment industry via "The Conan O'Brien Show". A segment that was shown on the show inserted the word "crunk" into songs that had a word dubbed out. The word was created to be a clean dirty word.
Alanis Morrisette's song "You Ought to Know" dubbed out the word "down" in the phase, "I would go *down* on you in a theater". With the word crunk inserted, the new phrse became "I would go *crunk* on you in a theater".
1)Crunk is the feeling you get when you are at the club,at home, at a party, or anywhere else where you can dance, party etc.
It's the feeling that says "god damn I'm havin a good time!" or "I'm feelin' like partyin' all da way out"