mut·ter·ing
noun/ˈmʌtərɪŋ/
/ˈmʌtərɪŋ/
[uncountable]- (also mutterings [plural])complaints that you express privately rather than openly
（私下的）抱怨，牢骚 - There have been mutterings about his leadership.
底下对他的领导一直怨声不断。
- There have been mutterings about his leadership.
- words that you speak very quietly to yourself
喃喃自语