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).
flight; proof; temptation; delicate ...
Hitchcock's Bible Names Dictionary
(the great eagle) an idol of Nineveh, in whose temple Sennacherib was worshipping when assassinated ...
William Smith's Bible Dictionary