Easton's Bible Dictionary (1897)
Champion of El; man of God, a descendant of Cain (Gen. 4:18), so called, perhaps, to denote that even among the descendants of Cain God had not left himself without a witness.
Smith's Bible Dictionary (1863)
(man of God), the son of Mehujael, fourth in descent from Cain, and father of Lamech. (Genesis 4:18)
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
METHU'SAEL (man of God),father of Lamech, and the fourth in descent from Cain, Gen 4:18.
Hitchcock's Bible Names (1869)
who demands his death