c.1300, fede, northern Eng. and Scottish, from O.Fr. fede, from O.H.G. fehida "contention, quarrel, feud," from P.Gmc. *faihitha, noun of state from *faiho- (adj.), related to O.E. fæhð "enmity." The whole group is connected to modern Eng.
foe (q.v.). Sense of "vendetta"