1. to make less intense, strong, or effective; to reduce the force or sensation of something
2. to make a sound quieter or less sharp

Examples

• The thick carpet deadens the sound of footsteps.
• Cold weather deadens the pain in his injured knee.
• The medication deadens nerve sensitivity during surgery.
• Heavy curtains deaden the noise from the street.
• Time deadens the sharp edge of grief.
• The foam padding deadens vibrations in the machine.