Stg, also written as STG, is a text abbreviation that stands for “swear to God” and is used to express passionate belief or intense exasperation, as in I stg that I left my keys on the desk yesterday but now I can't find them. Stg.

What does stg in messages mean?

NTG means "Nitroglycerine" or "Need To go."

What does STK mean?

STK means "Shoot to Kill."