Easton's Bible Dictionary: M. G. Easton, M.A., D.D.
Silence, (comp. Ps. 94:17), the fourth son of Ishmael; also the tribe descended from him; and hence also the region in Arabia which they inhabited (Gen. 25:14; 1 Chr. 1:30).
There was also a town of this name in Judah (Josh. 15:52), which has been identified with ed-Domeh, about 10 miles southwest of Hebron. The place mentioned in the "burden" of the prophet Isaiah (Isa. 21:11) is Edom or Idumea.