Synonymous with the commonly used phrase, "
What's up"? Used by one who is looking to find an agenda of recent events.
The phrase "What's crack-a-lackin'?"
originated in ghettos, and was used by thugs and gangsters to find out the news about any recent crimes committed
in the area ('crack-a-lack' is derived from sound a gun makes when fired).
Guy 1: "Ay yo Tito, what's crack-a-lackin'?"
Guy 2: "Nothin my nig, but I
heard that JoJo got whacked last night at da club."
Guy 1: "Fo real yo? I heard they was
poppin' off, but I ain't know JoJo was whilin
like that!"