a/a 

To go dutch (i.e. to share equally some expense or cost between two or more person). An uniquely Hong Kong slang prevalent in the 1960s and 1970s, and sometimes still heard today. Comes from the medical term to mean "in equal parts."

Let's go a/a on the 10-dollar meal. That's five from each of us.

a/a by Robert Lee August 28, 2005

A/A 

All Ages. commonly used in naming events, concerts etc. to distinguish between 18+ shows (bar) or events that allow all ages as long as people have I.D to prove their age for alcohol consumption.

person: thank god ____ are playing an A/A show this friday, or i totally would not have been able to go!

A/A by fghtoffyrdmns February 28, 2011

A A 

Alcoholic Anonymous, an organization established to help people recover from alcoholism through 12 steps and spirituality.

A A is a program for people who cannot handle their drinking.

A A by jakmak52 January 22, 2006

a_a

The lazy version of the look of disapproval. Not related to A_A which is a sign of extreme happiness.

Look_of_disapproval: ಠ_ಠ
Lazy version: a_a

a_a by Xavier-Marxel February 17, 2010

A_A

a "very" happy face/smiley

girl:like I just got me a puppy A_A
guy: o.O

A_A by Big D May 13, 2005

A A 

The bra size for women that don't need bras

-Look at the bee stings on her
-Yeah probably wears an A A

A A by JKage September 26, 2007

A A 

The most commonly used type of battery

Hey, You got two A A batteries for my torch? I think its ran out of power!

A A by My_Immortal January 28, 2006