What does bye bye mean?

Answer 1

"Bye" is short for "goodbye" and means the same as "farewell" (originally Fare thee well). The word "goodbye" derives from the old English "God be with (ye)you". It is a form of blessing as one leaves, and the opposite of "hello".

Answer 2

Bye Means When You Talk To Some One And They Are Leaving You Will Say "Bye!"

Answer 3

"Bye bye," as a shortened form for "Goodbye" ("God be with you!"), means that someone is leaving.