obs

open Bolt Semi, this is a type of gun that was ruled an illegal machine gun by the ATF in 1982. It was decided that they were to easy to convert to full-auto.

the obs kg-9, the predecessor to the closed bolt kg99 or tec9, was ruled an illegal machine gun.

by Alex Lindsay March 27, 2008

ob

Prefix meaning "obligatory". Most commonly used when saying something otherwise offtopic in places like Slashdot where that is frowned upon. Can be used where something is expected but might otherwise be missing.

Jessica Simpson is an airhead.
ObTopic: Linux is cool.

ObDrama: But she said she liked him instead.

ObLanguagePolice: There is no such word as "alot".

by fax4voice3 December 28, 2005

OBS

Stands for Optimal Breast Size. OBS is the point at which the female chest is near perfect in dimensions; they are neither too small or too large, as Goldy Locks would put it, they're juuust right.

Lynn has a wonderful set of OBS, I wonder if they're real...

by David James Saniti February 28, 2008

OB

"Old Balls" usually used to make fun of someone because of their age, or on their birthday to make them feel old.

"Hey Ryan you have OB now that your 25"

by pobcat March 22, 2010

obes

obes (see obes)

Obes is Obes

by Obes October 22, 2003

OB

Older Boy. similar to Older girl or Little boy. if you are a girl and you are going out with and older boy OB.

I think i am going to the party, there will be OBs.

Are you going out with an OB?

by pooismylife June 11, 2011

ob

short for obvious; also obvs, obv, awe, and ib

"you gunna nail that chick tonight"

"ob"

by greg bush June 14, 2008