sheugh (plural sheughs)
- A ditch.
This usage current in rural areas of Ulster (Northern Ireland and northern Republic of Ireland) and parts of Scotland.
It is also used in (at least) the West of Scotland to refer to the space between the buttocks - not the anus or cheeks, but rather the area where the two buttock cheeks meet.
Colloquially used when labouring - "The sweat is running down the sheugh of my arse"