Smith's Bible Dictionary (1863)
(strong or stony), one of the places from which some of the captivity returned with Zerubbabel to Judea who could not show their pedigree as Israelites. (Ezra 2:59) Called Addon (Nehemiah 7:61)
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
AD'DAN (stony), Ezr 2:59; called also Addon. Neh 7:61. Its site is unknown.