stands for "Fat Kid Comment". In remark to any statement that a fat kid would say.
Me: "I just ate dinner, is it weird that I'm still starving"
You: "Wow, that was a FKC".
Me: "I love free samples!!"
Me: "I only eat the corner pieces of cake"
its a gang of hip hop dancers or something.
"hey that kids in the FKC gang, dont touch him!"