When you use a word or term you don't really know, kinda superficially.
Jim subscribes to dictionary.com's twitter, and he's always Cracker-jacking-it (the words) at me.
The white person version of nigger rigging, as in fixing something up in an unorthodox manner regardless of how it looks.
Person1: "What term do you use for a white person pulling a nigger rig?"
Person2: "Cracker Jacking"
slang for excellent quality, or fine ability in an occupation. In this case Realtor.
Rosemary whom is a superb Realtor introduces her associate Charlene and herself as cracker jack Realtors who will get the job done.