Boyd’s Bible Dictionary:
(peace). The place over which Melchizedek was king, supposedly Jerusalem (Gen. 14:18; Psa. 76:2; Heb. 7:1-2).
Concise Bible Dictionary:
1. Symbolical name given to Jerusalem (Psa. 76:2).
2. Probably the title of Melchisedec as king of peace (Gen. 14:18; Heb. 7:1- 2). Various cities, however, have been suggested. Some consider that Jerusalem is alluded to; Jerome was convinced that a town near Scythopolis, named Salem, was the true place; but others judge it to be a title.
Jackson’s Dictionary of Scripture Proper Names:
at peace: complete: perfect