1. in a manner that dulls, suppresses, or reduces the intensity, liveliness, or impact of something
Usage: often used to describe sounds, sensations, or emotional effects

Examples

• The thick carpet was deadeningly quiet, absorbing all sound from the hallway.
• The medication worked deadeningly on her pain, leaving her in a fog.
• The monotonous lecture continued in a deadeningly slow pace.
• The heavy curtains hung deadeningly still in the airless room.
• His voice grew deadeningly soft as he lost confidence.