Bid farewell is a common phrase used to say goodbye or take leave of someone. However, there are several other synonyms that can be used to replace this phrase. They include 'farewell', 'adios', 'so long', 'goodbye', 'take care', 'see you later', 'cheerio', 'ta-ta', 'au revoir' and 'adieu'. Additionally, in some situations, more formal phrases can be used, such as 'parting is such sweet sorrow', 'it was nice knowing you', 'may your journey be safe' or 'fare thee well'. Regardless of the phrase used, the sentiment behind them is to express a feeling of departing with respect and fondness towards someone.