Nacker is a made-up slur used for comical effect, it is a mix of a Nigga and a Cracker. It is meant to typically be used for a mixed person. The word can be used when you don't know what to call them, since they aren't fully of Black Descent, nor of White/European descent.
The word is also used for people with names both in First, Middle or Last of both white and black origin, such as âBraxton Quantaviousâ. It also finds use for someone who excels both at 'stereotypically' Black and White things, but just barely. Better explained in the Example case.
You can use the shortened phrase 'An NBC' to describe a Nacker.
Basketball Teammate: "That guy is such an NBC, his 3-Pointers always land on the rim!"
Friend: "So where are you from?"
Mixed Person: "Ah, well, my moms from England, my dads an African-American."
Friend: "Oh, so you're a Nacker!"
Mixed Person: "...So. Should we go to Mcdonalds or Popeyes?"
Friends: "I wish you could decide already! You gotta stop being such a Nacker."