"Feud" v "Feudal": Sound is not Meaning

A recent blog post commenting on one of mine asserts that:

David Friedman at his appropriately entitled blog “Ideas” compares contemporary patent litigation with feudal warfare.

What I compared it to was a feud system, a legal system whose rules are enforced by the threat of private force, something very common in the historical record. "Feud" and "feudal" sound the same, which makes it easy to confuse them, but the words are unrelated in both meaning and etymology.

The same mistake as interpreting "niggardly" as a racial slur.

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feudal (adj.)

1610s, from Medieval Latin feudalis, from feudum "feudal estate," of Germanic origin (cf. Gothic faihu "property," Old High German fihu "cattle;" see fee). Related to Middle English feodary "one who holds lands of an overlord in exchange for service" (late 14c.).

feud (n.)

c.1300, fede "enmity, hatred, hostility," northern English and Scottish; perhaps from an unrecorded Old English word or else from Old French fede, from Old High German fehida "contention, quarrel, feud," from Proto-Germanic *faihitha noun of state from adj. *faiho- (cf. Old English fæhð "enmity," fah "hostile;" German Fehde "feud;" Old Frisian feithe "enmity;" see foe). Sense of "vendetta" is early 15c. Alteration of spelling in 16c. is unexplained.

(Both from the Online Etymology Dictionary)