Uncles Knuckles Posted in U Best definition Uncles Knuckles 1.When you uncle fists you and your sibling at the same time.2. When your uncle literally punches your ass hole into the next dimension. “I hate my Uncles knuckles” How satisfied are you with the definition? Looking for Uncles Knuckles meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 70 times.