Ephes-dammim

boundary of blood, a place in the tribe of Judah where the Philistines encamped when David fought with Goliath (1Sam 17:1). It was probably so called as having been the scene of frequent sanguinary conflicts between Israel and the Philistines. It is called Pas-dammim (1Chr 11:13). It has been identified with the modern Beit Fased, i.e., "house of bleeding", near Shochoh (q.v.).

EBD - Easton's Bible Dictionary