1. Without speaking
   - mutely, wordlessly, taciturnly 
2. Without a sound
   - noiselessly, soundlessly

See also: silent

• superimposition
• superincumbent
• superinduce
• superinfect
• superinfection
• superintend
• superintendence
• superintendency
• superintendent
• superior
• superior alveolar artery
• superior cerebellar artery
• superior cerebral vein
• superior colliculus
• superior conjunction
• superior court
• superior epigastric veins
• superior general
• superior labial artery
• superior labial vein
• superior mesenteric artery
• superior ophthalmic vein
• superior planet
• superior pulmonary vein
• superior rectus