(the ancient Cyrus), the principal river of Georgia, Western Asia, rises in a branch of the Caucasian Mountains, a little to the N.W. of Kars, about N. Lat. 41°, E. Long. 42°. It has a northerly course through the Turkish dominions, and to within about 60 miles of Tiflis, when it turns suddenly in a S.E. direction, and, after passing that city, empties itself by several mouths into the Caspian. It receives the waters of the Araxes about 70 miles from its mouth, and becomes navigable for small vessels. Its length is estimated at about 520 miles.