Definition from Wiktionary, the free dictionary
sheugh (plural sheughs)
- A ditch, especially a field boundary ditch usually used to drain fields and mark their boundaries.
- 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"