"au revoir" is the standard "goodbye". To be more dramatic/formal, you could say "adieu".
Adieu
adieu
Adieu
adieu
Adieu.
adieu
Salut
Adieu
farewell and adieu can be said for GOODBYE FOREVER in french
French Fields - 1989 Hail and Farewell 3-6 is rated/received certificates of: Australia:G
Adieu mon amour.
au revoir, bon voyage