silencer
nounUK /ˈsaɪlənsə/
US /ˈsaɪlənsər/
A thing you put on a gun to make it quieter.
The spy screwed a silencer onto his pistol before entering the building.
OTHER MEANINGS
2. A device fitted to a vehicle's exhaust to reduce engine noise.
The mechanic replaced the rusty silencer under the car.
3. A person or thing that makes someone or something silent.
The new rules acted as a silencer on public criticism.
4. A device that reduces the noise of a machine or appliance.
The air conditioner's silencer kept the bedroom quiet at night.