qwag
Any substance, liquid, slime or muck that cannot be identified easily.  This word was founded and orginated in southern NJ, although some would argue its origin was closer to the Toms River area.  Those claims are pure qwag.
Jackie-   "Ewwww whats that mysterious gross stuff on your leg"

Shane- "I got qwag all over me" !!
Shane " man im Qwaggin'"