What does STO mean?Sticking Out Tongue
Other definitions of STO:
All of our slang term and phrase definitions are made possible by our wonderful visitors. If you know of another definition of STO that should be included here, please let us know.
How to use the term STO:
There are no example uses of STO at this time. We would greatly appreciate your contribution if you would like to submit your own!
More slang terms:
don't really care
So not my problem