“Well,” says Buck, “a feud is this way: A man has a quarrel with another man, and kills him; then that other man’s brother kills him; then the other brothers, on both sides, goes for one another; then the cousins chip in – and by and by everybody’s killed off, and there ain’t no more feud.”
– Mark Twain
The Adventures of Huckleberry Finn, Chapter 18. Buck Grangerford defines the concept of a feud for Huck. He is basically saying that a feud is passed on from generation to generation, but soon enough everybody is going to kill each other off within the feud.