The dirty, brown, non-fecal, scuff marks that are left on your freshly cleaned toilet seat after someone who has a dirty sweaty ass sits on your toilet, and squirms. This phenomenon is usually cured when the nasty culprit washes their dirty ass.
Jaslene yells to Cherise, "Girl is this shit on your toilet seat?" Cherise replies, "Naw girl its prolly,"booty dirt." "My brother don't know how to wash his nasty ass!"