An expression used when departing. Can be used interchangeably with the words "i'll holla 'atcha", "later", or "bye". Was originally brought into existance by some douche bag from the "The White Rapper Show" on VH1.
Some stupid ass slang term Jon Brown from VH1's The white Rapper Show uses to fuckin much. It's also just as stupid as that ghetto revival shit he got.(you really doin it King of the Burbs).
Man we bout to get that Ghetto Revival shit crackin, hallejuah holla back son.
Separately, hallelujah means praise the Lord, while hollaback means reply. So, combined, it means praise the lord for answering my prayers. Usually used when the Lord sends a fine piece of booty across your field of vision.
Leeroy: Daaaaaaaaammnnn look at that fine piece of booty...
John Brown: Hallelujah hollaback!