sock on door knob 

Means we're fucking don't come in.

Tod is I'm there.
No don't go in there is a sock on door knob.
Oh ok tod is getting a little lucky.

sock on door knob by fitzy_2v May 30, 2016

doorsock 

A warning signal which is made by placing a sock over the doorknob of a bedroom door. This signifies to a roommate that you are inside the bedroom, engaged in sexual behavior.

I was headed into my bedroom to grab my wallet, but I stopped when I saw the doorsock and I knew my roommate was inside banging his girlfriend.

doorsock by itfitz April 21, 2006

doorsock 

signal that bathroom is occupied

Look at the doorsock, someone must be using the lavatory. Maybe it's Slutsky.

doorsock by dcsockman December 7, 2011

doorsock 

Doorsocks are flexible, snakelike, round, tubes filled with water absorbent material that stops air flow. Typically these tubes are used under doors, window sills, and other openings to stop air drafts, absorb rain or other water leaks, and reduce heating and cooling costs in the home.

After placing a doorsock against the inside of my front door the uncomfortable chilly air drafts stopped and my heating bill was reduced by more than 10%.

doorsock by Doorsocks.com August 24, 2006