mut·ter 
/ˈmʌtɚ/ verb
mut·ters; mut·tered; mut·ter·ing /ˈmʌtɚ/ verb 1 : to speak quietly so that it is difficult for other people to hear what you say [+ obj] ▪ She angrily muttered something about her bad luck. ▪ He muttered an apology. ▪ a muttered comment [no obj] ▪ She sat practicing her speech, muttering to herself. 2 [no obj] : to complain in a quiet or indirect way
▪ Some employees are muttering about the changes in the pension plan.
▪ Some employees are muttering about the changes in the pension plan.
— mutter noun, plural mutters [count]
▪ She answered with/in a mutter.
▪ She answered with/in a mutter.
— muttering noun, plural mutterings
[noncount] ▪ There has been some muttering among the employees. [count] ▪ We've been hearing mutterings from some employees about the changes in the pension plan.
[noncount] ▪ There has been some muttering among the employees. [count] ▪ We've been hearing mutterings from some employees about the changes in the pension plan.
