|Easton's Bible Dictionary|
A tooth, probably some conspicuous tooth-shaped rock or crag (1 Samuel 7:12), a place between which and Mizpeh Samuel set up his "Ebenezer." In the Hebrew the word has the article prefixed, "the Shen." The site is unknown.
Int. Standard Bible Encyclopedia
shen (ha-shen, "the tooth" or "peak"; tes palaias): A place named only in 1 Samuel 7:12 to indicate the position of the stone set up by Samuel in connection with the victory over the Philistines, "between Mizpah and Shen." The Septuagint evidently reads yashan, "old." Probably we should here read yeshanah, as in 2 Chronicles 13:19 (OHL, under the word). Then it may be represented by `Ain Sinia, to the North of Beitin.
Shen (1 Occurrence)
1 Samuel 7:12 Then Samuel took a stone, and set it between Mizpah and Shen, and called its name Ebenezer, saying, "Yahweh helped us until now." (WEB KJV JPS ASV DBY WBS YLT NAS NIV)