PTSan 20.b:16[2] :משתין בכתלא‏ : (the dog) urinates on the wall
See the entire entry for kṯal, kuṯlā n.m. wall

PTSan 20.b:16[2] :מה עיסקיה דכלבא משתין בכתלא‏ : what is the nature of the dog? It urinates on the wall
See the entire entry for štn vb. C to urinate