stg stands for 'small tits girl'. Generally used to describe a female person (or virtual character) with small-sized breasts.
The abbreviation can (relatively) safely be used among friends in public places, without raising suspicion of the person in question.
(First seen being used in source-code of some game as a reference to a female npc)
person A: Hey, you see that stg at 3 o'clock?
person B: That blonde? Yeah, so?
Person A: She's cute!
Person B: Dude... why do you always go mental about planks?
It is an abbreviation for "swear to god"
U realy Got expelled?
Aptly stands for 'Super Tan Girl'; a combination of a Gina and Valley Girl into one entity. Usually blonde, but is based on the overexcessive and obvious fake bake the girl has undergone.
Also associated with the more popular crowd, but not necessarily meaning that they are.
"Do you think that she went on vacation?"
"No, she's just an STG"
"That girl over there is such an STG"
"tell me about it, she could support the whole bronzing industry single-handedly"
Sexually Transmitted Glitter- Normally happens when you have sex with a stripper or glitter skanks
Guy 1- "did u hear about Shawn?? Yea he hooked up with that stripper Sapphire the other night, his face looks like he got Glitter Bombed"
Guy 2- "Yea man, he got a STG"
Its am Anagram for Stupid Teenage Girl.
Why are there so many STG's out there!
Shreddin The Gnar.
"Yeah son, we were STG the whole way."
Sexually Transmitted Guilt
The guilty feeling you contract from hooking up with someone you probably shouldn't have.
I hooked up with this random guy last night, I definitely have a serious case of STG
Spotted the Gay! Used to say that you see a homosexual person......without them knowing.
Miguel: Aye do you see that guys hair over there?
Habib: Yeah it is highlighted and spikey!
Miguel: I wish I had hair like him...
Habib: Me too
(Homosexual guy walks buy)
Habib and Miguel: STG!!!!!!!
Habib: Good thing we said STG because if we screamed "GAY" I think he would be offended.