devocalize or devocalise /dē-vōˈkə-līz/ or devoice /dē-voisˈ/

To make voiceless

• joylessly
• joylessness
• joylessnesses
• joyous
• joyously
• joyousness
• joyousnesses
• joypad
• joypads
• joypop
• joypopped
• joypopping
• joypops
• joyridden
• joyride
• joyrider
• joyriders
• joyrides
• joyriding
• joyridings
• joyrode
• joys
• joystick
• joysticks
• joy-wheel