What is another word for byebye?
Pronunciation: [bˈa͡ɪɪbˌa͡ɪ] (IPA) 
"Byebye" is an informal way of saying goodbye, and there are several synonyms that one can use depending on the situation. "Farewell" is a more formal way of saying goodbye, often used in professional or official settings. "See you later" is a friendly way to say goodbye, implying that you'll see the other person again soon. "Take care" conveys concern for the other person's wellbeing and safety. "Adieu" is another formal way to bid farewell, often used to signify a final goodbye. "Goodbye" is a common and neutral way to say goodbye, often used in both formal and informal settings. Ultimately, the synonym chosen depends on the context and the relationship between the speaker and listener.
