Informal goodbyes are often used in casual conversations and can be used to express a variety of sentiments. The crossword solutions for the term 'informal goodbye' include 'CIAO' (4 letters), 'LATER' (5 letters), 'PEACE' (5 letters), 'tata' (4 letters), and 'staycool' (8 letters). CIAO is an Italian word that is used as a friendly greeting or farewell. LATER is a phrase that is used to indicate that one will see someone at a LATER time. PEACE is a word that is used to wish someone well-being and safety. Tata is a Hindi word that is used to bid someone farewell. Staycool is a phrase that is used to wish someone to remain calm and relaxed.