Douglas Harper's Etymology Dictionary
Wiktionary
mill-race
n. (alternative form of mill race English)
Usage examples of "mill-race".
The central current, checked by the islets filling about a third of the total breadth of the river, funnelled at the gaps in midstream, gushing through with the speed of a mill-race.
Inlet where the rip of the tide runs a mill-race, or just off Kadiak on the Saanach coast, where twenty miles of beach boulders and surf waters and little islets of sea-kelp provide ideal fields for the sea-otter.
Listen to me: Pasquale Arispe says that in three days the arroyos on the hacienda of Don Lancelot will run like a mill-race.