Skid marks

[Mark Zuckerberg]

A line of fecal matter in your underwear that varies in thickness from thin to meaty. Usually a result of poor asswiping skills.

[Luis Fok]

A line or [a spot] of [fecies] left in ones underwear, either because they didnt wipe properly or they did not get all [the poop] out of their anus.

[Kit]

The combination of [white underwear] with a person with minimal butt wiping skills, or, someone, like Tom, who wears the same pair of [undies] for [3 days].

[Ernesto]

1. burned rubber marks left by tires [peeling] out

2. the [thin brown line] in your undies, especially [tightie-whities], caused by insufficient wiping

[Vania]

used to describe [the brown] marks in [unwashed] tightey whiteys belonging to someone who just couldnt hold it. or, alternatively, they had an all day [wedgie].

[Gregory]

black marks made by the tyres of a car when it starts or stops moving very quickly: