A prolonged form of a primary root; to bite, i.e. (figuratively) thwart -- bite.
a. properly, with the teeth.
b. metaphorically, to wound the soul, cut, lacerate, rend with reproaches: Galatians 5:15. So even in Homer, Iliad 5, 493 μῦθος δακε φρενας, Menander quoted in Athen. 12, 77, p. 552 e., and times without number in other authors.