Probably connected with the Hebrew word nesher, an eagle. An Assyrian god, supposed to be that represented with the head of an eagle. Sennacherib was killed in the temple of this idol (2 Kings 19:37; Isa. 37:38).
Nisroch
Sennacherib king of Assyria had gone home to Nineveh after his army was turned back from Jerusalem. Then, “as he was worshipping in the house of Nisroch his god,” two of his sons killed him with the sword and fled, and another son, Esarhaddon, became king (2 Kings 19:37; Isaiah 37:38). Nisroch is named only in these two matching accounts, and Scripture tells nothing more about this god. The verses are plain about what happened to the king inside his god’s house.
4 verses
2 Kings
2 Kings 19:36
So Sennacherib king of Assyria departed, and went and returned, and dwelt at Nineveh.
2 Kings 19:37
And it came to pass, as he was worshipping in the house of Nisroch his god, that Adrammelech and Sharezer his sons smote him with the sword: and they escaped into the land of Armenia. And Esarhaddon his son reigned in his stead.
Isaiah
Isaiah 37:37
So Sennacherib king of Assyria departed, and went and returned, and dwelt at Nineveh.
Isaiah 37:38
And it came to pass, as he was worshipping in the house of Nisroch his god, that Adrammelech and Sharezer his sons smote him with the sword; and they escaped into the land of Armenia: and Esarhaddon his son reigned in his stead.
From Easton's Bible Dictionary
Matthew George Easton, 1897
From Smith's Bible Dictionary
William Smith, 1884
(the great eagle) an idol of Nineveh, in whose temple Sennacherib was worshipping when assassinated by his sons, Adrammelech and Shizrezer. (2 Kings 19:37; Isaiah 37:38) This idol is identified with the eagle-headed human figure, which is one of the most prominent on the earliest Assyrian monuments, and is always represented as contending with and conquering the lion or the bull.