suppressor

Short definition from Wiktionary

Noun

1. 1
   A device which suppresses something, especially an electronic or mechanical device.
2. 2
   A device which suppresses something, especially an electronic or mechanical device: A device added to the barrel of a firearm which reduces the noise and flash generated by firing the weapon.
3. 3
   A person who suppresses others, a tyrant.
4. 4
   A gene that suppresses the effect of another through epistasis.