Origin and history of ker-

"state of being disordered or ruffled," hence "agitation, perturbation," 1813 (carfuffle), first attested in Scottish writers, from a verb meaning "to disorder, dishevel" (1580s), of obscure origin, probably from a dialect word based on Scottish verb fuffle "to throw into disorder" (1530s). The first element is perhaps as in kersplash, etc. (see ker-); OED points rather to a Gaelic car "twist, bend, turn about".

"churlish, miserly fellow, mean man," 1570s, of unknown origin. Drant (1568) translating Gregory of Nazianus, calls someone "a bolde curmogine chuffe." Liberman says the word "must have been borrowed from Gaelic" (and references muigean "disagreeable person"), with variant spelling of an intensive prefix represented by ker-. Related: Curmudgeonly.

The suggestion that it is from French coeur mechant "evil heart" is no longer taken seriously; nor is the notion that it is a corruption of corn merchant (with the notion of "one who withholds food"), which is attested by 1836. Liberman also dismisses the notion that the first syllable is cur "dog."

The minor poet Kynaston in late 17c. has murgeon "grimace, quaint gesture."

Sea-monsters, who up from the deep were come,

Presented a delightful antic dance,

Who on the waters' surface nimbly swome,

Making odd murgeons with their looks askance,

["Leoline and Sydanis"] 

variant of ker-.