uuny Posted in U Best definition uuny Uuny is when you have cum (or sperm, if you will) on the face. dude one: me and michelle totally smashed it in my room. dude two: man you’ve got uuny. How satisfied are you with the definition? Looking for uuny meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 29 times.