adieu adieu /əˈduː/

noun

1. () A farewell remark  ( arrivederci , au revoir , auf wiedersehen , bye , bye-bye , cheerio [Informal, British] , good day , good-by [American] , goodby [American] , adieu , adios , good-bye [ N. American] , goodbye , sayonara [American] , so long [Informal] )
   a farewell remark
    They said their good-byes
   they said their good-byes