n. 25B6; verb they grumbled about the disruption : COMPLAIN, grouse, whine, mutter, bleat, carp, cavil, protest, make a fuss; informal moan, bellyache, beef, gripe, bitch, grouch, whinge, sound off; Brit. informal chunter, create; N. English informal mither; N. Amer. informal kvetch.
25B6; noun his customers' grumbles : COMPLAINT, grouse, grievance, protest, cavil, quibble, criticism; informal grouch, moan, whinge, beef, bitch, gripe.