- a water channel, especially one built to lead water to or from a point where its energy is utilized, as in a mill or mine. See also millrace.
late Old English, from Old Norse rás 'current'. It was originally a northern English word with the sense 'rapid forward movement', which gave rise to the senses 'contest of speed' (early 16th century) and 'channel, path' (i.e., the space traversed). The verb dates from the late 15th century