word up !

Co znaczy "word up", taki phrasal verb?

I have been hearing the phrase word up meaning "You are so right" lately. How did this develop? I can't seem to make any connections that explain this new meaning. Thanks for your help in understanding my community college students......
Znajdziesz:

http://www.randomhouse.com/wotd/index.pperl?date=2[tel]

Thank you. It's a very useful article.
I don't know how you ferreted it out :)

google - ( 12sek i gotowe)