Easton's Bible Dictionary (1897)
Adod, brave(?). (1.) A son of Ishmael (Gen. 25:15); in 1 Chr. 1:30 written Hadad. (2.) One of the Edomitish kings (Gen. 36:39) about the time of Saul. Called also Hadad (1 Chr. 1:50, 51). It is probable that in these cases Hadar may be an error simply of transcription for Hadad.
Smith's Bible Dictionary (1863)
[Hadad]
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
HA'DAR (room). Gen 25:15. See Hadad. Gen 36:39. See Hadad, 2.
Hitchcock's Bible Names (1869)
power; greatness