STG
STG (abbreviation) means an abbreviation of "swear to God", used in text messages and online to insist that what you are saying is true or to express exasperation. Example: “STG if he cancels on me one more time I'm done.”
How to use STG
Learner’s notesIn plain EnglishShort for "swear to God" — a way of saying you really mean it.
Informal texting shorthand; lower-case "stg" is more common than capitals.
Watch the position: at the start of a sentence it usually means annoyance, at the end it means "honestly, this is true".
Trace the full origin ↓Fill the gap
Can you complete this real example?
_____ if he cancels on me one more time I'm done.
Etymology
An initialism of "swear to God"; the currency sense is a contraction of "sterling".