
Grumble
Subtle discontent
Used to indicate a mild or repressed annoyance without confrontation.

She grumbled about the cold office but didn't request a heater.
Not Directly
Expressing complaints indirectly, without addressing someone specifically.

Walking away from the meeting, Jonah grumbled about the decision.
Low Volume
Grumbling is not loud; it's quiet and may not be fully audible to others.

He grumbled to himself about the homework load.
Compare with
BellyacheComplainGripeGrouseMoanMurmurMutterWhine
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