1. a person who murmurs or speaks in a low, indistinct voice
2. a person who complains or expresses dissatisfaction quietly

Examples

• The murmurer in the back row made it difficult for others to hear the lecture.
• She was known as a chronic murmurer who always found fault with management decisions.
• The teacher asked the murmurer to speak up or remain silent.
• Even the quietest murmurer could be heard in the silent library.
• He was labeled a murmurer after constantly voicing his complaints under his breath.
• The murmurer’s soft protests went largely unnoticed by the crowd.