Gederah

the fortress; a fortified place, a town in the plain (shephelah) of Judah (Josh 15:36). This is a very common Canaanite and Phoenician name. It is the feminine form of Geder (Josh 12:13); the plural form is Gederoth (Josh 15:41). This place has by some been identified with Jedireh, a ruin 9 miles from Lydda, toward Eleutheropolis, and 4 miles north of Sur'ah (Zorah), in the valley of Elah.

EBD - Easton's Bible Dictionary