[{"Bold_text": "verb (used without object)", "List Items": ["to murmur or mutter in discontent; complain sullenly:Tim always found something to grumble about.", "to utter low, indistinct sounds; growl :Suddenly I heard my stomach grumble, and realized I hadn't had any lunch.", "to rumble:The thunder grumbled in the west."]}, {"Bold_text": "verb (used with object)", "List Items": ["to express or utter with murmuring or complaining."]}, {"Bold_text": "noun", "List Items": ["an expression of discontent; complaint; unhappy murmur; growl.", "grumbles,a grumbling, discontented mood.", "a rumble ."]}]