Definition of mill-tail in US English:

mill-tail

noun

  • 1The water downstream from a mill which has passed through the mill-wheel; the channel in which water runs away after passing through a mill.

  • 2Chiefly US regional. In similative and figurative use, denoting rapid movement, furious activity, or violent, unstoppable force.

Origin

Mid 16th century. From mill + tail.

Pronunciation

mill-tail

/ˈmɪlteɪl/