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Cyclopedia of Biblical, Theological and Ecclesiastical Literature [1]

the Graecized form of the name of the idol Hadad (Josephus, Ant. 8, 5, 2); also a less correct form of the name of King Hadad ( 1 Kings 11:17, original). (See Hadad).

Kitto's Popular Cyclopedia of Biblial Literature [2]

Ad´ad is the name of the chief deity of the Syrians, the sun. The name of this Syrian deity is most probably an element in the names of the Syrian kings Benhadad and Hadadezer.