Elster, the name of two German rivers. 1. The White or Great Elster rises in the W. of Bohemia, flows N. to Saxony, and joins the Saale near Halle, after a course of 115 miles. The Pleisse and Parde flow into it at Leipzig. 2. The Black Elster rises in Saxony, flows N. into Prussia, and then N.W. into the Elbe near Wittenberg, after a course of 100 miles. The Pulsnitz and the Roder flow into it.