Nadab (nāˈdăb) [key]. 1 Aaron's eldest son, set apart for the priesthood. The exact nature of the transgression ("offering strange fire") for which he and his brother Abihu died is not clear. 2 King of Israel, son and successor of Jeroboam I. He was assassinated by Baasha in the siege of Gibbethon. 3 Descendant of Jerahmeel. 4 Benjamite.