grumble

v. to complain about something in a quiet, unhappy way.

v. to murmur or mutter with discontent; to express dissatisfaction in a low, surly tone.

“The passengers began to grumble about the train delay after waiting for an hour.”

“The staff would frequently grumble about the new management's policies, though rarely did anyone voice these concerns during official meetings.”

v. to make a low, heavy sound like thunder or a hungry stomach.

v. to emit a low, continuous, and muffled sound; typically used for inanimate objects or physiological processes.

“I forgot to eat breakfast, and now my stomach has started to grumble.”

“Thunder began to grumble in the distance, warning the hikers that the clear afternoon sky was about to change.”

n. a quiet complaint or a feeling of being unhappy with something.

n. a surly or low-voiced complaint; an expression of minor discontent.

“There was a bit of a grumble from the crowd when the show started late.”

“Despite the general success of the project, there was a persistent grumble among the senior engineers regarding the lack of technical documentation.”

Informal

n. a low, deep sound that continues for a short time.

n. a low-frequency acoustic event, such as the sound of distant thunder or intestinal activity.

“The distant grumble of the volcano kept the villagers awake all night.”

“The low grumble of the heavy machinery provided a constant, vibrating backdrop to the daily life of the factory workers.”

Literary