What's on your mug?

basically it means online school

bro 1: I have os bro! bro 2: what's os bro 1: online school

By c9ole

Slang word for a power up in the popular game Halo 2 means Overshield. Gives you 2 extra layers of shield

"Pick up the OS you wont die!"

By Mex4life1992

Object Squad. A squad that forms in 201 and is used nothing more for their body. Some notable people featured in the OS squad are Sid the Sloth from Ice Age and coked up Jennifer Aniston.

OS has arrived, time to shut it down sorry boys, people only, no objects

By nbaboi23

The name Os comes from a dutchman rockspider originating from the small town in the Free State named Harrismith. He prowls the streets with his eyes closed but is still watching you so be very wary of this. Normally people with the name Os fall off boats whilst simply cruising off the Cape Point in 50 meters of water.

"watch out, the Os might be watching us"

By Nicliaus Bouwer

It stands of for oh shit

OS it's the manager

By Hassan 3bod