FEUD, animosity, hatred, especially a permanent condition of hostilities between persons, and hence applied to a state of private warfare between tribes, clans or families, a "vendetta." The word appears in Mid. Eng. as fede, which came through the O. Fr. from the O. High Ger. fehida, modern Fehde. The O. Teutonic faiho, an adjective, the source of fehida, gives the O. Eng. fáh, foe. "Fiend," originally an enemy (cf. Ger. Feind), hence the enemy of mankind, the devil, and so any evil spirit, is probably connected with the same source. The word fede was of Scottish usage, but in the 16th century took the form foode, fewd in English. The New English Dictionary points out that "feud, fee (Lat. feudum) could not have influenced the change, for it appears fifty years later than the first instances of foode, etc., and was only used by writers on feudalism." For the etymology of "feud" (feudum) see Fee, and for its history see Feudalism.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)