a river of Scotland, rises on the confines of Ayrshire, Kirkcudbrightshire, and Dumfriesshire, flows S.E. through Dumfriesshire, and falls into the Solway Firth after a course of 45 miles. The principal towns on its banks are New Cumnock and Dumfries, the latter about 8 miles from its mouth. The Nith has salmon fisheries of considerable value. It has been rendered a classic stream by the poetry of Burns, who resided for some time at the farm of Ellisland, near Dumfries.