Definition: A command to be quiet, or less politely, to shut up!
Example: Mitchell was told to put a sock in it when he began the story of how his wife lost her skirt in the closing bus door.
Despite its relatively recent appearance, there seems to be no single accepted explanation for it.
Early gramophones had no volume controls, so people used to stuff the horn with a sock to reduce the volume. Boy, the world was a harsh place before the digital age. Next, you’ll be telling us that they had to hand crank a handle to get the record spinning. Oh. They did, didn’t they.
Like the expression ‘bite the bullet’, it originates from battlefield medical procedures. The unfortunate soul being operated on in the trenches had a sock or other item of clothing stuffed in his mouth to muffle his screams. This was for the benefit of the surgeon, the soldier’s comrades, and to stop the enemy from pinpointing their position from the noise.
Simplest of all, it is your overwhelming urge when cornered by a dreadful bore; to jam a sock into the offending orifice. And the smellier the sock, the better.