arse stain

1. A shit stain on ones backside. A smear of shit on ones bottom possibly caused by poorly wiping ones arsehole or deliberately smearing shit on a persons arse, thus causing an arse stain.

I'm still wiping off the arse stain.

Arse stained tattie

A way to call someone a potato dipped in shit. A general insult.

Sum Buddy: "Can I borrow 5 bucks?"
Appe Erson: "Fok off ya arse stained tattie"