Something that literally does not exist under any circumstances and is a made up term when a person can'tactually create a constructive argument so they resort to it as their backup plan.
Bob: "Hey! how come you didn't tell me about the one thing you didn't even know about?! You should know what it was! It's just common sense!"
Me: "what"
This word does not have a definition, but more of an underlying meaning that has been around since the beginning of time, kinda like the Chinese/Japanese fighter Ki (Chi/Qi) it goes:
Anyone can fix something that broken, but it takes a genies to fix something that's not broken.