One that silences, especially a device attached to the muzzle of a firearm to muffle the sound of firing. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "silencer" in a sentence
"A silencer is basically a muffler that can change the performace and sound of the snowmobile."
"Should any of them lose the luster off that lone dimension, be sure your silencer is on ... and then give 'em the ol 'heave-ho."
"I had an old Magnum .45 that I had had custom made for me, with a built-in silencer."