Methushael
From BiblePortal Wikipedia
Hastings' Dictionary of the Bible [1]
Methushael A Cainite, the father of Lamech, Genesis 4:18 (J [Note: Jahwist.] ); Methuselah in P [Note: Priestly Narrative.] ’s genealogy ( Genesis 5:21 ff.). The interpretations of the name are various.
International Standard Bible Encyclopedia [2]
mḗ - thū´shā́ - el ( מתוּשׁאל , methūshā'ēl ): A descendant of Cain, and father of Lamech in the Cainite genealogy ( Genesis 4:18 ). The meaning of the name is doubtful. Dillmann suggested "suppliant or man of God."