It replaces the word jackass with a word that no one knows.  Jay Z said it on his album, so I would tend to believe it means a Black person.  We have converted it to mean anything or anyone.  You could be black, white, jewish, indian, mexican, spanish, etc.  It doesn't matter who you are, your still a jzenna. It is also a word for someone who has more then you do.
Whats up you smelly Jzenna?  Hey jzenna, you seen my lighter?  Your a fucking Jzenna.  Don't be a fuckin jzenna you smelly jzenna.  What's up jzenna, what chu doing.   That guy is a jzenna.
by Jzenna December 3, 2007
 Get the jzennamug.
Get the jzennamug.