What does TBT mean?
If you remember back to your old chemistry classes in high school, then you probably know that TBT is the chemical compound Tributylin.
However, when you see TBT on Texting, Twitter, and Facebook these days, the sender is probably not referring to Tributylin.
TBT in the online world simply means "Truth Be Told."
"Truth be told," means that you are stating the truth when you don't really want to, but decide to anyway. Like when someone asks you if you think they are fat. Natural answer would be 'no' regardless, but instead you could say. "TBT, you are fat!"
TBT can also mean Throwback Thursday on Instagram. Basically, you post old pictures on Thursday, from the past. Going back in time with Throwback Thursday is always fun and interesting.