grumbling
🇺🇸
/ˈɡrʌmblɪŋ/
🇬🇧
/ˈɡrʌmblɪŋ/
complaining or expressing dissatisfaction in a low continuous sound or inarticulate way
There was a lot of grumbling in the office about the new work schedule.
a low continuous sound like a grumble
The grumbling of the thunderstorm made everyone nervous.