Smith's Bible Dictionary (1863)
(plain), The valley of, described (Genesis 14:17) as “the valley of the king,” is mentioned again in (2 Samuel 18:18) as the site of a pillar set up by Absalom.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
" Gen 14:17; 2 Sam 18:18. See King's Dale.
Hitchcock's Bible Names (1869)
the plain; that makes equality