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24.
o's
'The O's' is the nickname for East London footie club, Leyton Orient. Also for their rather nondescript hooligan crew.
by Ned September 20, 2003
 
1.
O's
ounces,particularly of crack
i cooked up ten o's last night.
by Devon W. February 12, 2006
 
2.
OS
Operating system. Simply, a program that runs your computer. Examples of an operating system are CP/M, DOS, Windows, Mac OS, Linux, and Palm OS, though there are many more. One will oftentimes become overly attached to their OS, preaching it as though it were a religion and shunning all who use anything even slightly different.
Man: My OS of choice is Windows XP.
Woman: My OS of choice is Mac OS X.
Man & Woman: (killing eachother)
Supa-Nerd: My OS of choice is CP/M! 8086 FOREVAH!!!
by Chow October 27, 2004
 
3.
OS
Abbreviation for Operating System

A good list of popular Operating Systems are listed here (taken from "www.bellevuelinux.org"):
AIX
Amiga
BeOS
Darwin
FreeBSD
FreeDOS
GNU/Hurd
HP-UX
IRIX
JavaOS
Linux
Mac OS X
Microsoft Windows
MINIX
MS-DOS
NetBSD
OpenBSD
Palm OS
QNX
SkyOS
Solaris
TRON
Tru64

An operating system is the main software that runs a computer, without an operating system a computer is almost useless.

There is no best operating system, they all have their advantages/disadvantages and were all developed with some kind of goal in mind.
1: All the company's servers used Unix (OS), but now they use Linux (OS).

2: George had a quadruple boot with multiple OSs running on his PC, it ran Microsoft Windows Vista Ultimate, Mac OS X Leopard, and two flavors of Linux.
by Klienmahn November 08, 2007
 
4.
os
the opposite of so. when a conversation dies, instead of saying so, say os. it will jump the conversation to a new level to keep the flow.
...dead silence.

os.

What ? Os ?

Yeah the opposite of so,.....proceed from here
by Will Hamilton March 10, 2004
 
5.
abbreviation of "one's self" sometimes used in dictionaries
French dictionary:
s'occuper
- to occupy o.s.
- to keep o.s. busy
by TomParys March 06, 2013
 
6.
os
An abbreviation for oh shit
"Os! Do you smell baby Sarah? I thought I changed her a few minutes ago."
"Os?"
"I don't wanna cuss in front of the child."
by kpbostonianakamrsadams June 22, 2009
 
7.
O.S
Oral Sex
That bitch gave me O.S Last night
by AC November 11, 2003