Simple past tense and past participle of grumble.(verb)
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Use "grumbled" in a sentence
"I divided and issued the meat under the captain's eyes, and managed it fairly enough, God knows, although some of the men grumbled from the first."
"I spend all afternoon picking out the clothes to wear for a night out on the town with the ladies, and I get upstaged by some guy dressed like Popeye, a Manhattan man who only identified himself as Austin grumbled as he surveyed the servicemen crowded into a neighborhood bar."
"The parson's daughter had had her way; Daddy Darwin grumbled at first, but in the end he got a bottle-green Sunday-coat out of the oak-press that matched the bedstead, and put the house-key into his pocket, and went to church too."