The accumulation of residue, in one's ass-crack, that appears after long periods of bodily neglect (read: poor hygeine). The residue is composed of various elements; the most common are: poop, ass pubes, accumulated sweat resin (aka: salt cream), hemroidal or vaginal medication residue, blood, lubricant, and fuzz from undergarments.

Residue, left on a toilet seat, usually in the shape of a "Y" (reflecting the reoccurring placement of an unwashed ass-crack, from one, or multiple persons), that collects over time, due to an insufficient cleaning/maintenance routine of the toilet in question; most commonly seen in gas station stalls. The composition of Bumslaw may vary; the most common elements include: poop, ass pubes, accumulated sweat resin (aka: salt cream), hemroidal or vaginal medication residue, blood, lubricant, and fuzz from undergarments.