Easton's Bible Dictionary (1897)
Or Thelasar, (Isa. 37:12; 2 Kings 19:12), a province in the south-east of Assyria, probably in Babylonia. Some have identified it with Tel Afer, a place in Mesopotamia, some 30 miles from Sinjar.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
TELAS'SAR, and THELA'SAR (the hill of Aushur), a place inhabited by the "children of Eden" and subdued by the Assyrians. 2 Kgs 19:12; Isa 37:12. Rawlinson puts it in Western Mesopotamia, near Harran and Orfa; Layard at Tell Afer, 40 miles west of Mosul.
Hitchcock's Bible Names (1869)
taking away; heaping up