goodbye
good-bye
interjection
An expression used to acknowledge departure or conclude a conversation.
"Goodbye, see you next week!"
noun
An act or instance of saying farewell when parting from someone.
"We said our goodbyes before leaving."
Thesaurus
Synonyms: sayonara, adios, good-by, good day, au revoir, so long, bye-bye, cheerio, bye, arrivederci, adieu, auf wiedersehen