Adrammelech
The name Adrammelech belongs to two distinct figures: a deity of Sepharvaim worshipped by the foreigners resettled in Samaria, and a son of Sennacherib who, with his brother, kills the Assyrian king in the temple of Nisroch.
The Sepharvite Deity
When the king of Assyria resettles the cities of Samaria with people from elsewhere in his empire, each transplanted group brings its own gods. Among them: "and the Sepharvites burned their sons in the fire to Adrammelech and Anammelech, the gods of Sepharvaim" (2Ki 17:31). The cult of Adrammelech is named together with that of Anammelech, and is marked specifically by child-sacrifice by fire — set inside the larger catalogue of foreign worship that the chapter records as the religious situation of the resettled north.
The Son of Sennacherib
The other Adrammelech is one of Sennacherib's own sons, named in the closing verse of the Assyrian campaign against Judah. After Yahweh strikes the Assyrian camp, Sennacherib withdraws to Nineveh, and his death follows: "And it came to pass, as he was worshiping in the house of Nisroch his god, that Adrammelech and Sharezer struck him with the sword: and they escaped into the land of Ararat. And Esar-haddon his son reigned in his stead" (2Ki 19:37).
The parallel notice in Isaiah is nearly identical and adds the relationship explicitly: "as he was worshiping in the house of Nisroch his god, that Adrammelech and Sharezer his sons struck him with the sword; and they escaped into the land of Ararat. And Esar-haddon his son reigned in his stead" (Is 37:38). Sennacherib falls inside the temple of his own god, by the hand of his sons; the assassins flee north to Ararat, and the throne passes to a brother, Esar-haddon.