Nephilim

Biblical offspring of the "sons of God" and the "daughters of men" before the Flood; of uncertain and much-disputed etymology.

The only obvious meaning of this Hebrew term is "fallen ones" — perhaps, those who have come down from the realm of the gods; but then the word might conceivably reflect an entirely different, un-Hebraic background. [Robert Alter, "The Five Books of Moses," 2004]