The story
- Scots · derived fromgullion“swamp; cesspool”
- English todayslumgullion
Uncertain, but said to derive from slime and Scots gullion (“swamp; cesspool”). Attested from the late nineteenth century in reference to a watery beverage (see quotation below). Compare Irish góilín (“a creek; a small inlet”).
Etymology from Wiktionary, CC BY-SA 4.0.