Adieu and Bye-byes

Adieu noun - An expression of good wishes at parting.

Bye-byes and adieu are semantically related In some cases you can use "Bye-byes" instead the word "Adieu" as a noun or a interjection.

Adieu and bye-byes are semantically related in departure topic. You can use "Adieu" instead the phrase "Bye-byes" as a interjection or a noun, if it concerns topics such as goodbye, farewell statement, have a nice trip.