A term used when someone insults you, such as a nerd, geek, loser or scum. Usually shuts them up. If not, repeat, with heavy emphasis on the Geek part.

Pronunced "Sit down, Geek." Make sure you pause.
NerdyJim112: Hey you suck dude!
Tony: Sit down, Geek.
NerdyJim112: ......
by Ultramatic March 14, 2008
Get the Sit down, geek mug.