A "Laddj", is a penis, or more commonly called, a jur jur. The point with "Laddjing" is to slap your laddj in the face of someone you know. If you are laddjed, you cant use violence against the laddjer. To get back at him you need to laddj him yourself.
z0mg!!1 kiMMi was just laddjing Leif so hard in his eye! Awesome!