Hello, everyone. I need some help with the next phrase: "You're white-knuckling it, living like this". What does to white-knuckle mean? In case you need some context, this phrase was said in a tv show called "Supernatural", season 6, chapter two. Someone told this to Dean (one of the main characters) after he had been a little paranoid about the safery of some people. He was totally overprotecting them, in a way that was rather frightening.