ATG 

Ass-to-Grass. A type of squat in weight lifting where one goes as deep as possible.

1)I'm squatting ATG today for 5x5.
2)If you want to get swole, you gotta squat ATG!

ATG by Mr. Deeds October 25, 2006

ATG 

All time great

ATG NBA superstar Allen Iverson was inducted into the Naismith Memorial Basketball Hall of Fame on April 4, 2016.

ATG by bjscool May 18, 2016

ATG 

ATG=Any Thing Goes. Usually said in conversation before a crazy night out with someone.

"what you wanna do tonight?"
"Idk, ATG."
"Aright that's cool with me"

ATG by NervousClassGoerSaysRoar September 7, 2012

ATG 

ATG (Anti-thymocyte globulin or AtgamÒ) is a medicine used prevent rejection in different types of transplantation, treatment of graft versus host disease and in certain patients with aplastic anemia. It does this by suppressing the body's own immune system. It is available as an injectable medication.

Got some shitty news about the ATG tonight. It's not working.

ATG by q February 1, 2005

ATG 

abbreviation for 'at the gym'

brb lol atg.

ATG by trano December 30, 2011

ATG 

According to Google

ATG the sun rises from the east.

ATG by S2NV February 15, 2019

ATG 

ATG stands for Autistic Tongue Group. People who stick their tongues out when they take selfies are classified as an “ATG”.

You’re now officially an ATG for taking a selfie with your tongue sticking out.

ATG by cherryvaginaslayer December 31, 2018