Originally "throwback Thursday" but now often used on other days. Can now stand for "throwback to" to indicate an old photo, thought, idea, etc. Often used in social media to reminisce, as usually social media is supposed to show the "here/now/recently."

A slang abbreviation for truth be told

taco bell time

thinking bad thoughts

The definition of TBT is "Truth Be Told"

TBT means "Truth Be Told"

to be true

To be tested