@mookie For what it's worth, the word really confused an American friend of mine who was over here studying in the early '90s.
She overheard two people talking about "Going to the chippy for a butty."
Chips = fries. Chippy = place that sells fries (and other fried food). Chip butty = "fries in a sandwich".
I had no idea chippy was an American slang term for sex worker. She was shocked how casually and cheaply you could get a "butty" from a "chippy" over here. 😆