1. Characterized by soft sounds
   "a murmurous brook"
   - rustling, soughing, susurrous

See also: murmur, soft

• prothrombin
• prothrombin accelerator
• prothrombinase
• protirelin
• protist
• Protista
• protistan
• Protium
• Protium guianense
• Protium heptaphyllum
• proto
• Proto-Indo European
• Proto-Norse
• proto-oncogene
• protoactinium
• protoanthropology
• protoarchaeology
• protoarcheology
• protoavis
• protoceratops
• protocol
• protoctist
• protoctist family
• protoctist genus
• protoctist order