Arse, backside, rear end. Derived from the Old East Slavic гузно, which historically referred to the rump, tail end, or backside of an animal or bird. In modern Russian, it is a vulgar-colloquial, dialectal, or slightly archaic noun for the human buttocks or anus.
Палец кнутобойца указывал на гузно его превосходительства. Повыше нахлестанного места, где копчик, виднелась малая картинка: красный цветок навроде ромашки.
The whipper’s finger was pointing to His Excellency’s bottom. Above the whipped spot, where the coccyx was, was a small picture: a red flower like a daisy.
(Борис Акунин, Внеклассное чтение, 2003)
