Melchizedek in Fausset's Bible Dictionary

("king of righteousness".) King of Salem (Jerusalem) and priest of the most high God (Elion; used by Balaam, Numbers 24:16. The Phoenicians so named their chief god according to Sanchoniathon in Enseb. Praep. Event., doubtless from primitive revelation. After the slaughter of Chedorlaomer Melchizedek met Abram in the valley of Shaveh (level), the king's dale (Genesis 14:17-20; 2 Samuel 18:18), namely, the valley of the upper Kedron, where Absalom long afterward reared a pillar; adjoining Jerusalem. Salem was the oldest, the poetic name (Psalm 76:2), Jebus was the next name, and Jerusalem is the most recent name. This favors the view that Siddim, Sodom, and Gomorrah were to the S. of the Dead Sea. Abram in returning from Dan to Hebron would naturally take the route by Jerusalem (Thomson, Land and Book, 2:31). Adonizedek ("lord of righteousness") corresponds; being also the name of a king of Jerusalem (Joshua 10:1)...