grutch

The verb is from Middle English grucchen (attested since c. 1200), from Old French grouchier (“to grumble”), of unknown origin, perhaps from Germanic, and likely of onomatopoeic origin. Compare Frankish *grōtijan (“to accuse, yell at, make cry, scold”). The noun is from Middle English grucche, from the verb; it is attested since about 1400. See also grudge, grouch, grouse.