Bye is a common term used to say goodbye, and there are many variations of it. FAREWELL is an 8 letter word that is often used as a formal way to say goodbye. CIAO is a 4 letter word that is commonly used in Italian and Spanish speaking countries. ADIEU and ADIOS are 5 letter words that are used in French and Spanish speaking countries respectively. PASS is a 4 letter word that is used to say goodbye in some parts of the United States. Tata is a 4 letter word that is used to say goodbye in India. Husha is a 5 letter word that is used to say goodbye in some parts of the United States. LATER is a 5 letter word that is used to say goodbye informally. Seeya and Seeyou are 5 and 6 letter words respectively that are used to say goodbye informally. Solong and Aurevoir are 6 and 8 letter words respectively that are used to say goodbye informally. Toodleoo, Gottasplit, Imoutahere, Itsbeenfun, Seeyousoon, and Takeiteasy are all 10 letter words that are used to say goodbye informally.